The family of a prominent Parisian art dealer is demanding that a Norwegian museum return an Henri Matisse painting seized by the Nazis during World War II.

The painting at the center of the dispute, Matisse’s 1937 “Blue Dress in a Yellow Armchair,” depicts a woman sitting in a living room. It has been among the highlights of the Henie Onstad Art Center near Oslo since the museum was established in 1968.

Museum Director Tone Hansen said the museum did not know the painting was stolen by the Nazis until it was notified last year by the London-based Art Loss Register.

She said Onstad bought the painting in “good faith” from the Galerie Henri Benezit in Paris in 1950. Disputes over looted art have become increasingly common, in part because many records were lost, and in part because an international accord on returning such art was struck in 1998.

But the case of the Matisse is somewhat different in that its former owner, Paul Rosenberg, was one of the most prominent art dealers in Paris before the war, which he survived by fleeing to New York. Art Loss Register Director Chris Marinello said the records in this case are unusually clear. Art Registry documents show Rosenberg purchased “Blue Dress” from the painter in 1937, Marinello said. After the war, he sought to recover more than 400 works that had been taken by the Nazis.

Paul Rosenberg died in 1959. Among surviving descendants are French journalist Anne Sinclair.

The lawyer representing the museum, Kyre Eggen, said it was significant that Onstad didn’t know where the painting came from. Under Norwegian law, if a person has had an item in good faith for more than 10 years, that person becomes the rightful owner, he said.

That argument runs against the Washington Conference Principles on Nazi-Confiscated Art, to which Norway is a party. The principles say that owners of looted art should take into account the difficulty that Jewish war survivors faced in reclaiming lost property after the Holocaust, and that owners of looted art should in all cases seek a fast and fair solution.