The Geneva public prosecutor has confirmed a criminal investigation is underway after authorities searched the Geneva Freeport for a contested painting by Amadeo Modigliani, details of which were revealed in the Panama Papers.

The Modigliani painting, known as “Seated Man with a Cane,” was being stored in the freeport facility until it was seized by authorities following a search last week.

The painting, which may be worth as much as $25 million, is at the center of a legal battle between the estate of a Jewish art dealer and an art dynasty controlled by David Nahmad.

The Nahmads have insisted in federal and state court in New York that the family does not possess the Modigliani. An offshore company called International Art Center, registered by a little-known Panamanian law firm, does.

But according to the Panama Papers investigation, the Nahmad family has controlled the Panama-based company, International Art Center, for more than 20 years, and David Nahmad, the family leader, has been the company’s sole owner since January 2014.

According to the Swiss newspaper Le Temps, the prosecutor’s office conducted a search of the premises of the art storage company Rodolphe Haller, which has already told the U.S. court that it was storing the painting on behalf of IAC.

On Monday, a spokesan for the prosecutor’s office confirmed an investigation had been opened and the painting had been seized.