An unnamed Russian billionaire and his son have launched a lawsuit against their art dealer, who helped them build a collection worth an estimated CHF 600 million ($607 million). The family is alleging that the dealer inflated prices to defraud them of millions.

The collector, a Baltic industrialist living in Geneva, Switzerland, is accusing the dealer, also based in Geneva, of committing fraud while brokering sales of works by Claude Monet, Pablo Picasso, Breugel the Younger, Joan Miró, and Francis Bacon, according to an investigation by the Tribune de Genève.

The dealer in question, who has yet to be named in the press, is apparently not well known to local gallerists. According to documents the Tribune obtained from the Geneva courts, he says he only received a five percent commission on the artworks, totaling CHF 30.8 million ($31 million).

The collector said in the legal complaint obtained by the Swiss paper that when he hesitated at the cost of a painting, the dealer offered to forego his commission. The dealer also used multiple offshore shell companies to acquire the paintings, such as Servin International, United Trade Development Company, Finatrading Development, and Wang Tak Trading Development, allegedly to protect the client’s identity. Several of these offshore companies were set up by another local art dealer, Yves Bouvier, also known as the “Freeport King.”

Although Bouvier is not named as a party to this lawsuit, he has apparently been heard as a witness in the case. Incidentally, Bouvier is embroiled in a similar legal battle with Russian mining magnate Dmitry Rybolovlev. Both Rybolovlev and the current plaintiffs live in the affluent Geneva neighborhood of Cologny, according to the Tribune de Genève. 

Bouvier could not be reached for comment. A representative for him told artnet News that they had no knowledge about the present case.

The new case also mirrors the ongoing Rybolovlev saga in other ways. Bouvier helped Rybolovlev assemble a staggering collection of art worth more than $2 billion over the course of their 11-year business relationship. But the Russian claims Bouvier defrauded him out of as much as half of that by inflating the prices of 38 works and pocketing the difference. The most notable transaction involved Leonardo da Vinci’s Salvator Mundi, which Bouvier allegedly marked up by $47.5 million. 

The extensive coverage of the Rybolovlev case in the media alerted this second unnamed Russian art collector that the same thing might have happened during his own collecting.

The Public Prosecutor’s Office of Geneva confirmed to artnet News that this investigation was ongoing but declined to comment. The Office of the Attorney General of Switzerland says it is not involved in the case at present.

UPDATE, July 10: The Art Newspaper reports that the Russian collector behind the lawsuit is Vladimir Scherbakov, an automobile magnate who has also played a major role in Russian politics. Scherbakov declined to comment to the newspaper.