“We want our looted work back. Full stop”, the descendant of Jewish art dealer and victim of Nazi spoliation, Paul Rosenberg, has told the New York Times.

Marianne Rosenberg is incensed by the suggestion that she should have to buy back Edgar Degas’ ‘Portrait of Mlle. Gabrielle Diot’ (1890) after it was looted from her grandfather’s house by the German ambassador. The pastel portrait was one of 400 works stolen from the Parisian art dealer by the Nazis when the Rosenberg family fled France.

Thanks to Paul’s meticulous records of his collection, his descendants have managed to recover all but 60 pieces. Mlle. Diot’s portrait continues to elude them despite the fact that she has surfaced several times since her disappearance when a German dealer has attempted to sell her.

The Rosenberg family first rediscovered Mlle. Diot when she appeared in a sale catalogue of Hamburg art dealer, Mathias Hans in 1987. When Marianne’s mother, Elaine Rosenberg, telephoned Hans to enquire about the portrait, he said confidentiality rules prevented him from disclosing the consignor’s identity and insisted the Rosenberg family buy it back from him. When Elaine refused to buy the work back, Hans told her it would be returned to the consignor and she would never get it back.

“I cannot understand on any level why a family that has been looted by the Nazis should have to pay to get its property back,” Marianne stated, “There is no excuse for this behavior and this unwillingness to return this work, which they know is looted”.

After the portrait went unsold in 1987, Hans placed it on the market again in 2003. Finally, in 2016, the German Culture Ministry intervened to request the contact details of the consignor. Under the Washington Principles, the German government is obliged to help return Nazi-looted works to their owners. However, when the Ministry contacted Hans to request the consignor’s details, Hans responded that his client wanted the Rosenbergs to pay them the 3.5 million Swiss francs (£2.7 million) it had cost them to purchase the portrait in 1974.

The Rosenberg’s claim is further complicated by German law. While the law states that a good faith purchaser cannot pass good title to a stolen work, theft claims must be made within 30 years. Further to this, after 10 years the possession rights of the painting’s current owners override those claiming restitution unless it can be shown they knew the work was stolen at the time of purchase.