Fearing Nazi theft, a Swiss museum removes artwork.

Claude Monet's Jardin de Monet à Giverny is one of the paintings that have been taken down from the Emil Bührle Collection's exhibition.

Leading Swiss art museum said it will take five artworks out of an exhibition as it looks into possible Nazi looting of the paintings. The pieces, which are a part of the Kunsthaus Zurich museum's collection, are by some of the most well-known artists in the world, such as Vincent van Gogh and Claude Monet. The provenance of some of the pieces in the Emil Bührle Collection, which bears the name of an arms trader of German descent who amassed wealth by producing and supplying weapons to the Nazis during World War II, has long been the subject of suspicion.

The choice to remove the paintings was made in response to the release of new rules intended to address the issue of the numerous cultural artefacts that have yet to be returned to the original owners. The following pieces of art are being examined: Claude Monet's Jardin de Monet à Giverny; Gustave Courbet's Portrait of the Sculptor Louis-Joseph; Henri de Toulouse-Lautrec's Georges-Henri Manuel; Vincent van Gogh's The Old Tower; and Paul Gauguin's La route montante. In a statement, the Emil Buhrle Collection's foundation board stated that it was "committed to seeking a fair and equitable solution for these works with the legal successors of the former owners, following best practices".

La Sultane, a painting by Edouard Manet that is the sixth piece in the collection, has also come under closer examination. However, the foundation stated that it did not think the new standards applied to the artwork and that it will be evaluated individually. "Due to the overall historical circumstances relating to the sale, the Foundation is prepared to offer a financial contribution to the estate of Max Silberberg in respect to the tragic destiny of the former owner," read the statement. German Jewish industrialist Silberberg's vast art collection was thrown into sale by the Nazis. It is believed that he was killed during the Holocaust at the Nazi death camp at Auschwitz.

The Neue Zürcher Zeitung newspaper claims that there has been discussion on Silberberg's decision to sell La Sultane, specifically whether he did it voluntarily or because it was necessary for financial gain.

Switzerland was among the more than 20 nations who earlier this year accepted updated US State Department best practices about handling Nazi-looted artwork. These were released in commemoration of the Washington Conference Principles' 25th anniversary in 1998. The principles outlined in the document sought to compensate victims of theft or forced sales of property. Since there are currently no statutes of limitations that allow for the legal pursuit of restitution or compensation for items from the Bührle collection, the principles provide a crucial avenue of action for families who want to reclaim stolen art.

During the announcement of the best practices in March, Stuart Eizenstat, the US Secretary of State's special advisor on Holocaust issues, stated that it was estimated that "over 100,000 of the 600,000 paintings and many more of the millions of books, manuscripts, ritual religious items, and other cultural objects stolen have never been returned". Before his passing in 1956, Bührle accumulated over 600 pieces of art. Many of these are under the management of the Bührle Foundation and have been lent to the Kunsthaus for a period of 20 years. The remaining ones are reportedly hanging in Bührle's living relatives' houses.