The report found 62 works in the foundation's collection had belonged to Jewish owners during the Holocaust.

In 2001, a museum official said the work's provenance was "concerning."

Genealogy experts identified the ownership of the two works, which had been on display since the 1950s.

The heirs of two Jewish art collectors have both claimed they should be allowed to have the work, which was consigned to Christie's.

The State Department marked the 25th anniversary of the Washington Principles with new guidelines on the restitution of Nazi-looted items.

The collective described collector Emil Georg Bührle as "a Nazi sympathizer."

German culture minister Claudia Roth said a resolution over Madame Soler was "really overdue".

The work's original theft was dated to 1941 by a panel overseeing restitution.

Among the collection is Klimt's Roses Under the Trees, which was sold under duress in 1938.

Düsseldorf had initially rejected restitution claims brought by the original owner's heirs.