A Parisian engineer is suing New York’s Metropolitan Museum of Art to recover a Paul Cezanne painting that he says the Bolsheviks stole from his great- grandfather during the Russian Revolution. The suit was filed Tuesday in U.S District Court.

The painting is valued at $50 million to $70 million, said Washington lawyer Allan Gerson, who represents the plaintiff, Pierre Konowaloff. A New York dealer in Impressionist art, who didn’t want to be identified, said that in today’s market, it could sell for as much as $100 million.

“Madame Cezanne in the Conservatory,” painted in 1891, was a 1960 bequest of Stephen C. Clark, an heir to the Singer sewing machine fortune, according to the museum’s website. In his complaint, Konowaloff claims that Clark bought the dour portrait of the artist’s wife in May 1933 “in violation of Russian law and U.S. policy” because it was months before the U.S. diplomatically recognized Soviet Russia.

The Met said in a statement that it has been open about the provenance and will fight the suit.

Read the full Bloomberg story, “Met Museum Sued Over Cezanne Painting Stolen by Bolsheviks From Collector.”