In October 2020, a gold EID MAR Aureus of Brutus fetched 3.24 million British pounds at a London auction. The coin was genuine. This is precisely what makes the case so remarkable: it wasn’t its authenticity that later became a problem, but rather its provenance.
In March 2023, the New York State Attorney General’s office wrote that the aureus first appeared on the international art market in 2016 and was offered for sale in Munich without provenance. Later, it was offered with an alleged provenance from the collection of Baron Dominique de Chambrier. The New York criminal complaint described this provenance as forged. In 2023, the coin was confiscated and returned to Greece along with other antiquities.
This case illustrates a distinction that is easily overlooked in the coin trade. A coin can be undoubtedly genuine, professionally identified, and even examined by a grading service – and yet its legitimate provenance can still be unclear or problematic.
This raises a broader question: Are private collectors and dealers a risk to cultural heritage because cultural goods enter private hands and the market? Or can they, precisely because of this, be part of the protection system – because they preserve, document, publish, and later make these pieces recognizable?
There is no simple answer to that. German law does not treat private collecting and trading as the antithesis of cultural heritage protection. Rather, the decisive factors are which objects are being traded, where they come from, and how traceable their history is .
Short answer
The protection of cultural heritage in the case of coins does not mean that private collectors and coin dealers are fundamentally opposed to cultural heritage protection. The Cultural Heritage Protection Act itself assumes the free movement of cultural goods as long as no prohibitions or restrictions apply. At the same time, it requires due diligence in cases of problematic provenance and imposes additional verification and documentation obligations on commercial dealers. With coins, it is particularly important to note: not every old coin is automatically an archaeological cultural asset, not every cultural asset is “nationally valuable,” and a genuine or certified coin does not automatically possess a legally sound provenance.
What does cultural heritage protection actually mean when it comes to coins?
In common parlance, “cultural property” quickly conjures up images of museums, archaeological sites, and state protection. The German Cultural Property Protection Act (KGSG) uses the term much more broadly. According to Section 2 of the KGSG, movable objects can be considered cultural property, among other reasons, because of their historical, archaeological, or explicitly numismatic value .
However, this does not mean that every collectible coin is automatically under special state individual protection.
A second, much narrower category is nationally valuable cultural property . For an object to be entered in a corresponding register, Section 7 of the German Cultural Property Protection Act (KGSG) requires that it be particularly significant and identity-forming for the cultural heritage of Germany, a state, or a historical region, and that its removal would represent a substantial loss for German cultural property.
A high market price alone is not enough.
This distinction is crucial for collectors: “cultural property” is a broad legal term. “Nationally valuable cultural property,” on the other hand, is a distinct special category.
Equally important is the principle in Section 20 of the Cultural Property Protection Act (KGSG). According to this, cultural property may, in principle, be imported, exported, and placed on the market, provided that the law or other regulations do not stipulate prohibitions or restrictions. The law therefore does not begin with a general ban on trade, but rather with freedom of movement under legal conditions.
Are old coins automatically considered archaeological cultural heritage?
No. The legislator has explicitly included a distinction, especially regarding coins.
Section 42 paragraph 3 KGSG contains a rule specifically tailored to coins: Coins are not considered archaeological cultural property under this provision if they are present in large numbers and have no relevant value for archaeology .
This distinction is important for the coin market. A common type of coin that has circulated in trade for decades and whose find context no longer provides any scientific information is to be assessed differently from a coin from a newly discovered, undocumented hoard.
A complete coin find can be more than the sum of its individual parts. The find location, composition, chronological layering, and shared deposition can provide historical information. If such pieces are illegally excavated and sold individually, this context can be irretrievably lost.
We have already seen this in the major coin thefts: In the case of the Manching hoard, part of its scientific value lay precisely in the coherent composition of the find. Therefore, the protection of cultural heritage is not only about who owns a coin , but, in the case of archaeological objects, also about what information is preserved or destroyed by their provenance .
What should a private collector consider?
The general due diligence obligations of Section 41 of the German Cultural Property Protection Act (KGSG) do not only apply to professional dealers. Anyone who places cultural property on the market must, in principle, check whether it has been lost, illegally imported, or unlawfully excavated.
However, the law does not require a private seller to conduct a full scientific provenance research for every ordinary coin.
The standard is that of a reasonable person. Active scrutiny becomes particularly relevant when the circumstances should give rise to suspicion. The law specifies two typical warning signs in the case of a previous purchase: an exceptionally low price without a plausible explanation and the request for cash payment for a purchase price exceeding €5,000.
The crucial question, therefore, is not: “Can I prove the history of this coin without gaps over the centuries?” But rather: Are there concrete circumstances that reasonably suggest a problematic origin?
The risk situation is naturally different for a modern proof gold coin from a verifiable trade than for an allegedly newly discovered ancient gold stater without an invoice, find history or previous market evidence.
How collectors can practically verify the provenance of a specific piece—slab, certificate number, photos, and existing provenance information—is already covered in our article “Numismatic Buying Guide: Checking Provenance with Cooper .” This article focuses on the legal and cultural policy aspects behind it.
The audit standards are higher for retailers.
Anyone who commercially distributes cultural property is subject to additional due diligence obligations under Section 42 of the German Cultural Property Protection Act (KGSG). The law specifies seven concrete points.
| Test | What does § 42 KGSG require? |
|---|---|
| Participants | Determine the name and address of the seller, consignor, buyer or client. |
| Identity of the object | Create a description and illustration that can be used to identify the cultural asset. |
| Provenance | Check origin story |
| Import and export | Check existing documents for legal import and export |
| Prohibitions and restrictions | Check relevant trade, import and export rules |
| Databases | Check whether the object is listed in publicly accessible directories and databases. |
| Right of disposal | Obtain a declaration from the consignor or seller that they are authorized to dispose of the object. |
For provenance, document, legal and database checks, the standard of reasonable, in particular economically reasonable, effort generally applies.
However, these additional obligations do not apply in every case. According to Section 42, Paragraph 3 of the German Cultural Heritage Protection Act (KGSG), they do not apply if the cultural asset is not an archaeological asset and its value does not exceed €5,000 . The general rules of Section 41 are separate from this.
The law also answers the obvious question for dealers, “Which value actually counts?”: In the case of a purchase, the price actually paid is decisive; in other cases, a justified domestic appraised value applies.
This is practically relevant for coins because the same regulation contains a special rule for frequently occurring pieces without significant archaeological value. The value limit was raised from €2,500 to €5,000 in 2025. Archaeological cultural property remains excluded from this exemption.
When do particularly strict requirements apply?
Section 44 of the KGSG (German Act on the Protection of Children and Young Persons) specifies cases in which economic feasibility cannot be used as a limitation of the audit obligations.
This includes, in particular, cultural assets for which confiscation due to Nazi persecution between 1933 and 1945 has been proven or is suspected, as well as cultural assets from countries for which the International Council of Museums (ICOM) has published a Red List of endangered cultural property. In addition, certain EU-wide trade or import bans apply.
Furthermore, the €5,000 relief under Section 42 Paragraph 3 does not apply in these cases.
The logic behind this is quite clear: the higher the identifiable risk of a compromised origin, the less a professional market participant can limit themselves to examining only the obvious.
Why 30 years of documentation?
Commercial inspections pursuant to Section 42 must be recorded in accordance with Section 45 of the German Commercial Code (KGSG). The associated documents and evidence must be retained for 30 years .
This seems unusually long at first. However, the time horizon for cultural artifacts is different than for ordinary consumer goods. A rare coin can reappear on the market after ten, twenty, or fifty years. Invoices, auction catalogs, photographs, and previous descriptions then themselves become part of its traceable market history.
Especially with long-lasting collection objects, documentation is therefore more than just bureaucracy. It can later make the difference between a mere assertion and a verifiable provenance.
Private collectors are not subject to the same 30-year record-keeping requirement under Section 45. Nevertheless, it is advisable to retain invoices, auction records, correspondence, and informative photographs for the long term. Our guide to documenting a coin collection shows how such documents can be systematically recorded.
The EID MAR aureus: genuine is not the same as legitimate
The EID-MAR case makes the difference particularly clear.
The aureus was not a forgery. Its numismatic authenticity was not the central issue in the subsequent dispute. According to the published account of the New York investigation, the piece initially lacked a verifiable provenance when it first appeared on the market. Later, it was offered for sale with an alleged history of being part of an old collection.
This case illustrates a limitation of technical authentication: A grading service can assess whether a coin is genuine and its condition. However, this does not automatically imply that the consignor is the owner, that the export from a country of origin was legal, or that the stated ownership history is accurate.
For modern certified coins, the risk of illegal excavation is usually minimal. Nevertheless, the fundamental distinction remains the same: authenticity, condition, ownership, and provenance are four distinct issues.
Can one acquire a stolen collector’s coin in good faith?
German civil law provides a particularly interesting answer for coin collectors.
According to § 935 of the German Civil Code (BGB), ownership cannot generally be acquired in good faith if an item has been stolen from, lost, or otherwise gone missing from the owner. The law provides exceptions, including for money and for items sold at a public auction.
“Public auction” does not simply mean “an auction in which anyone can participate.” According to the current version of Section 383 Paragraph 2 of the German Civil Code (BGB), it must be conducted publicly by a publicly appointed and sworn auctioneer or a competent bailiff. It can now also take place virtually or in a hybrid format. Therefore, an ordinary online auction is not a public auction within the meaning of this property exception simply because it is accessible via the internet.
This leads to a seemingly simple question regarding coins: If a Krugerrand or a Euro gold coin is legal tender, does it fall under the exception for “money”?
The Federal Court of Justice answered this question in 2013 in a coin case that was practically tailor-made for the situation.
During the night of December 31, 2008, to January 1, 2009, a property owner had gold and silver bars, Krugerrands, German “Weimar” gold coins with a face value of 100 euros, and Austrian Vienna Philharmonic silver coins with a face value of 1.50 euros stolen. The subsequent purchaser argued, among other things, that the coins constituted money within the meaning of Section 935 Paragraph 2 of the German Civil Code (BGB).
The Federal Court of Justice clarified: Collector coins that are neither intended nor suitable for circulation in payment transactions do not become “money” within the meaning of this regulation simply because they are officially approved as a means of payment.
In the case of the Krugerrand, the court pointed out that its primary function is not in payment transactions and that the coin does not have a readily identifiable face value. Regarding the German 100-euro gold coins and the 1.50-euro silver coins, another argument was added, one particularly relevant to today’s precious metals trade: their material value was significantly higher than their face value. An economically prudent owner would therefore not use them as ordinary means of payment at their face value.
This case is therefore far more than a legal curiosity. It shows that the inscription of a face value or the status of legal tender on a collector coin does not automatically mean that it is treated like ordinary cash under civil law.
Why reputable trading can be part of the protection system
The protection of cultural heritage is often portrayed as a conflict between state authorities on the one hand and private collectors or dealers on the other. In practice, this division is too simplistic.
A stolen or illegally excavated object often only becomes visible when it re-enters a regular market channel: through an auction consignment, a dealer purchase, a database check, or a professional appraisal.
The international coin trade has therefore developed its own ethical rules. The Code of Ethics of the International Association of Professional Numismatists obliges members, among other things, not to knowingly trade pieces stolen from public or private collections or that are reasonably suspected of being the result of illegal excavations. Members are also required to ensure lawful ownership, accurately state provenance and description, and assist authorities.
The IAPN Lost Coin Archive is the association’s own warning system for lost and stolen numismatic objects.
Of course, this doesn’t make the trade infallible. The EID-MAR case proves precisely the opposite: expertise and market position don’t automatically protect against misconduct. But it doesn’t follow that trade as such is contrary to the protection of cultural property. The crucial question is whether its structures create or obscure transparency .
What private collectors contribute to cultural heritage
Private collections are not simply final destinations where cultural assets are withdrawn from public view.
Collectors can preserve pieces for decades, keep old provenances together, maintain auction catalogs and correspondence, document variants, and build up knowledge about rare years or stamps that may not be available to the same depth in public institutions.
Private collecting becomes problematic when the desire for possession becomes more important than the question of origin.
This is especially true for archaeological objects. Anyone who buys an undocumented find is not only acquiring an object with an unclear legal history. In the worst case, they are financially rewarding precisely the process that destroyed the context of the find and scientific information.
Conversely, a well-documented private collection can later be extremely valuable for research and market history. Provenance is then not merely a selling point. It is a record of where an object was located, when it became known, and under what circumstances it changed hands.
The real conflict is not between the museum and the private collection.
The simple comparison of “museum or private property?” therefore leads in the wrong direction.
German cultural property law explicitly recognizes private ownership and the free movement of cultural property. At the same time, it sets limits in cases of theft, illegal excavation, unlawful import, and specially protected cultural property.
The more meaningful contrast is therefore:
documented legal ownership versus undocumented or illegal origin.
A museum can make a mistake in a problematic acquisition. A private collector can build an exemplary, well-documented collection. A dealer can recognize a stolen coin and inform investigators. And a professional market participant can manipulate provenance information.
Institution type and integrity are not the same thing.
What does this mean for collectors of modern gold coins?
For the typical collector of modern numismatic gold coins, an illegal archaeological find is hardly an everyday occurrence. Nevertheless, the principles are relevant.
For high-quality modern coins, it should be possible to trace the origin of a piece, how it can be identified, and what documentation belongs to it . For certified coins, slab and certificate numbers, previous photographs, and sales records help to identify a specific specimen even after changes of ownership.
This not only protects against counterfeits. It also makes it easier to clarify the situation if a coin is later reported stolen or if doubts arise about its ownership.
Our article ” When coin treasures disappear – spectacular numismatic thefts” shows how valuable such information can become even decades later.
For professional dealers, there is another level to consider: documentation is not only good business practice, but depending on the coin and its value, it can be a legal requirement.
Conclusion
Private collectors and dealers are neither automatically guardians nor automatically opponents of cultural heritage.
Legal coin trading can preserve objects, disseminate knowledge, document provenance, and bring stolen pieces back into the public eye. Private collectors can preserve collections for generations that would otherwise be scattered or lost.
However, both can also become part of a problem if questions of origin are deliberately ignored, suspicious offers are accepted, or provenances are artificially created.
The Cultural Heritage Protection Act attempts to draw precisely this line. It does not prohibit collecting. It assumes the free movement of cultural goods, but requires due diligence where origin and legality become questionable, and imposes additional responsibility on professional dealers.
For numismatics, this is not a trivial legal question. A coin doesn’t just bear a motif, metal, year of issue, and grade of preservation. Ideally, it also carries a verifiable history.
Frequently asked questions about coins and cultural heritage protection
Is every old coin automatically a cultural asset?
No. While the German Cultural Property Protection Act (KGSG) defines cultural property broadly and explicitly mentions numismatic value, whether a specific coin falls under this definition depends on the individual case. Furthermore, “cultural property” is not the same as “nationally valuable cultural property.”
Is every ancient coin an archaeological cultural asset?
No. The German Cultural Heritage Protection Act (KGSG) explicitly contains a special rule for coins. If coins exist in large numbers and have no relevant archaeological value, they are not considered archaeological cultural property under Section 42, Paragraph 3.
Is it legal to privately own and collect antique coins?
Private collecting is generally not prohibited. The decisive factors are the legal origin and, where applicable, import, export, and conservation regulations. However, objects from illegal excavations or unlawful imports can lead to significant legal problems.
Must a provenance extend seamlessly back to the minting date?
No. The German Cultural Heritage Protection Act (KGSG) does not require an unbroken chain of ownership spanning centuries for every object. The specific scope of the review depends on legal obligations, the risk involved, and what is reasonable to expect. The more conspicuous or sensitive an object is, the more important reliable evidence of its past ownership becomes.
Can I become the owner of a stolen collector coin if I knew nothing about the theft?
According to § 935 of the German Civil Code (BGB), the acquisition of ownership in good faith of stolen or otherwise lost property is generally excluded. There are statutory exceptions. However, the German Federal Court of Justice (BGH) has expressly ruled that collector coins do not fall under such an exception simply because they are legal tender.
Does an NGC or PCGS slab prove a clean provenance?
No. A slab can, in particular, document the identity, authenticity, and condition of the specific piece. Ownership, legal export, and complete provenance are separate issues.
What documents should a collector keep?
Useful documents include purchase invoices, auction records, correspondence, previous provenance information, high-quality photos, and, for certified coins, the certificate number. The more valuable and rare a piece is, the more important permanently verifiable documentation becomes.
About the author
Dirk Wasserthal is co-founder and managing director of Wasserthal RareCoin.Store. He deals with rare certified gold coins, international trade routes, and the question of how the origin, identity, and market history of a collector’s item can be verifiably documented.
Transparency note
Wasserthal RareCoin.Store deals in rare, certified gold coins and therefore has a vested interest in a functioning and trustworthy international coin market. This article provides general information and context. It does not replace individual legal advice. In particular, the specific legal situation should be professionally examined in cases involving ancient coins, archaeological finds, cross-border acquisitions, or specific ownership disputes.
Sources and further documents
- Law on the Protection of Cultural Property (KGSG) , in particular Sections 2, 7, 20 and 40–45; current version after amendment of July 17, 2025.
- Federal Government: Amendment to the Cultural Heritage Protection Act 2025 – Increase of the relevant value threshold from 2,500 to 5,000 euros.
- KGSG § 42 – Due diligence obligations in commercial marketing , current consolidated version; in particular paragraph 3 on the 5,000 euro limit, the coin rule and on valuation.
- German Civil Code, § 935 – No acquisition in good faith of lost property.
- German Civil Code, Section 383 Paragraph 2 – Definition and implementation of public auctions.
- Federal Court of Justice, Judgment of June 14, 2013 – V ZR 108/12 .
- Manhattan District Attorney: DA Bragg Returns 29 Antiquities to Greece , March 21, 2023 – Primary source on the appearance of the EID-MAR-Aureus 2016 in Munich without provenance and on its return.
- International Association of Professional Numismatists: Code of Ethics .
- International Association of Professional Numismatists: Lost Coin Archive .
- Coin World: Authorities arrest dealer, repatriate record-setting coin , 2023.
Legal status: September 1, 2026.
