A Martian meteorite that sold for $5.3 million at auction this year has become the subject of a complex legal dispute involving questions over its provenance and ownership. The 54-pound specimen, touted as the largest meteorite from Mars ever found, was auctioned by Sotheby’s in July 2025 but has since been seized by U.S. federal authorities.
Sotheby’s initially reported that the meteorite was discovered in 2023 in Niger’s desert region. However, the government of Niger launched an investigation into whether the sale violated its 1997 law protecting the country’s natural heritage. Following this inquiry and concerns about the meteorite’s legal acquisition, Sotheby’s paused the sale to reassess the situation.
U.S. federal agents later confiscated the rock, citing its importation to the United States without proper customs declaration. Jeanine Pirro, the U.S. attorney for the District of Columbia, declared in a recent public statement that the government now claims ownership of the meteorite. She argued that no record exists of it entering the U.S. legally and described the transaction as part of a suspicious scheme.
Sotheby’s had promoted the sale based on information from an anonymous seller who allegedly traveled to Niger after receiving a tip from a meteorite hunter. Some meteorite experts questioned this narrative, noting that Niger’s political instability in 2023, which included a coup d’état, would have made such a trip into remote desert areas difficult for foreigners.
Sources close to the meteorite trade suggested the rock was actually found in southern Algeria by a Bedouin and subsequently sold to a Moroccan dealer. To circumvent Algeria’s ban on meteorite exports, the specimen was reportedly reclassified as originating from Niger. Luca Cableri, a collector with a controversial past and accused connections to a major historical library theft in Europe, was reportedly involved in brokering the sale. Cableri stated he sold the meteorite to a private party but denied knowledge of its subsequent movements.
The consignor listed for the Sotheby’s auction was Matthew Williams, known for dealing in fossils. Neither Williams nor Sotheby’s has released detailed records concerning the meteorite’s chain of custody or import documentation. Auction house Christie’s reportedly declined involvement in the sale due to questions over the object’s provenance.
Brenton Easter, a Homeland Security Investigations agent specializing in cultural property crimes, monitored the Sotheby’s auction and alerted federal prosecutors, leading to the enforcement action to seize the meteorite.
If the government prevails, the meteorite may become U.S. property through forfeiture. Legal experts suggest the rock could then be returned to its country of origin, auctioned again, or donated to a museum. Pirro declared readiness to take possession of the meteorite and emphasized the government’s position that the United States now owns the piece until proper ownership is established.