(Bloomberg) -- Geneva prosecutors opened a criminal probe into the ownership of an Amedeo Modigliani painting that was stolen by the Nazis in World War II as part of a New York legal dispute over the $20 million art work.

As part of the case, investigators on Friday searched facilities at the Geneva Free Ports, and confiscated the painting, “Seated Man with a Cane,” the Geneva Prosecutor’s Office said in a statement Monday.

Current ownership of the Modigliani canvas was disclosed as part of the millions of documents leaked from Panamanian law firm Mossack Fonseca, the Tribune de Geneve reported last week. The documents, known as the Panama Papers, have led to widespread revelations about offshore accounts owned by the rich and powerful. They have already forced the prime minister of Iceland to resign and put U.K. premier David Cameron on the defensive about his family’s finances.

The Modigliani painting, worth as much as $25 million, was taken by the Nazis from its original owner, Parisian art dealer Oscar Stettiner, who died before he could recover the piece after the war. Stettiner’s grandson hired Mondex Corp., a Toronto-based art recovery firm acting for the original owner, to track the canvas down.

Long Struggle

“This is a major victory for our client in his year’s long struggle to recover a valuable work of art he rightfully owns,” Mondex founder James Palmer said in the statement. The current ownership of the painting is “illegal” and “we look forward to working with Swiss authorities to recover a “Seated Man with Cane” and returning it to its owner,” he said.

The current owner of painting is the International Art Center, an investment firm owned by collector David Nahmad, the Tribune de Geneve reported, citing Mossack Fonseca. That backs up a lawsuit filed last year in New York court by Stettiner, claiming IAC was an off-shore entity used by the Nahmad family to hold their artworks, most of which are stored in the Geneva facility.

The Geneva Prosecutor’s office said it won’t comment further now that the case is underway. Aaron Golub, a lawyer for David Nahmad and International Art Center, said Friday in a phone interview that the location of the painting, “Seated Man with a Cane,” already had been known to the court.

IAC acquired the work at a 1996 auction at Christie’s in London for $3.2 million.  It was exhibited at the Helly Nahmad Gallery in 2005 and offered at auction at Sotheby’s in 2008, according to court filings. The painting, which was valued between $18 million and $25 million by the auction house, failed to sell.

The painting is worth about $20 million, according to the heir’s complaint, while Tribune de Geneve cites estimates of $25 million.

The New York case is Maestracci v. Helly Nahmad Gallery Inc., 650646/2014, New York State Supreme Court (Manhattan)

--With assistance from Jeffrey Vögeli To contact the reporters on this story: Hugo Miller in Geneva at, Edvard Pettersson in federal court in Los Angeles at, Katya Kazakina in New York at To contact the editors responsible for this story: Anthony Aarons at, Christopher Elser, Thomas Mulier

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