The heirs of a Jewish art collector persecuted by the Nazis are trying to get eight drawings held by London’s Samuel Courtauld Trust returned to them, but a U.K. government panel says their “moral claim” is insufficient.

The drawings, by Lovis Corinth, Pierre Auguste Renoir, Giuseppe Bernardino Bison, Giovanni Battista Crosato, Domenico Fossati, and Domenico Piola, were sold by the collector, Curt Glaser, in 1933, the year he was suspended from his job as director of Berlin’s Art Library and thrown out of his apartment by the Gestapo. He sold most of his collection in two auctions that year and subsequently fled for Switzerland. The eight drawings, now at London’s Courtauld Gallery, were purchased at a Berlin auction in 1933 and bequeathed in 1978 to the Courtauld Trust. Glaser’s heirs insist that he was forced to sell the works to fund his escape and that therefore the sale was not legitimate. But the Spoliation Advisory Panel, founded to resolve disputes about art lost in the Nazi era that is now held in British museums, rejected their argument. The heirs’ lawyer says he will contest the decision.