A legal battle over two Picasso paintings has begun between two major New York art museums and the descendant of the paintings’ original owner, who claims that the works were forcibly sold in Nazi Germany, reports The New York Times.

The Museum of Modern Art and the Solomon R. Guggenheim Foundation, which oversees the Guggenheim Museum, asked a federal court last week to declare them the owners of the paintings — “Boy Leading a Horse” (1906) and “Moulin de la Galette” (1900), respectively.

“Boy Leading a Horse” was donated to MoMA by the founder of CBS, William S. Paley, in 1964. The art dealer Justin K. Thannhauser donated the other Picasso to the Guggenheim in 1963.

Lawyers for Julius H. Schoeps, the great-nephew of the paintings’ original owner, Paul von Mendelssohn-Bartholdy, say the works were sold to Mr. Thannhauser under pressure from the Nazis. They have demanded the return of the paintings. Mr. Schoeps’s lawyers offered no comment for the article.

Thomas Krens, director of the Guggenheim, says, “Both museums feel this claim is without merit. This is a serious issue, and we want to take the most direct path to confirm it.”

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