German art historian Meike Hoffmann has been trying to establish the origin and value of around 1,500 artworks found in Munich that were looted by the Nazis in the 1930's and 1940's.
One of the works was reported to be a Matisse painting previously owned by Jewish collector Paul Rosenberg.
His granddaughter Anne Sinclair, the French journalist and ex-wife of the former head of the International Monetary Fund Dominique Strauss Kahn has been campaigning for many years for the return of looted art.
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