One of Switzerland's leading art museums says it will remove five paintings from one of its exhibitions while it investigates whether they were looted by the Nazis.

The works - part of a collection at the Kunsthaus Zurich Museum - are by some of the world's most acclaimed artists, including Claude Monet and Vincent van Gogh.

There have long been suspicions about the provenance of works in the Emil Bührle Collection - named after a German-born arms dealer who made his fortune during World War Two by making and selling weapons to the Nazis.

The decision to remove the paintings comes following the publication of new guidelines aimed at dealing with the large number of cultural works that have still not been returned to the families they were stolen from.

The artworks that are under investigation are Jardin de Monet à Giverny by Claude Monet, Portrait of the Sculptor Louis-Joseph by Gustave Courbet, Georges-Henri Manuel by Henri de Toulouse-Lautrec, The Old Tower by Vincent van Gogh, and La route montante by Paul Gauguin.

The foundation board for the Emil Buhrle Collection said in a statement it was "committed to seeking a fair and equitable solution for these works with the legal successors of the former owners, following best practices".

A sixth work in the collection, La Sultane by Edouard Manet, has also come under further scrutiny but the foundation said it did not believe the new guidelines applied to it and that the painting would be considered separately.

"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," it said.

Silberberg was a German Jewish industrialist whose extensive art collection was sold at forced auctions by the Nazis. It is thought he was murdered at the Auschwitz Nazi death camp during the Holocaust.

According to the Neue Zürcher Zeitung newspaper, there has been debate about whether Silberberg was forced to sell La Sultane or whether he freely did so for financial reasons.

More than 20 countries, including Switzerland, agreed earlier this year to new best practices from the US State Department about how to deal with Nazi-looted art.

They were issued to mark the 25th anniversary of the 1998 Washington Conference Principles, which laid out a set of principles aimed at making restitution for items that were either stolen or forcibly sold.

The principles are an important resource for families seeking to recover looted art as, under Swiss law, no legal claims for restitution or compensation can be made today for works from the Bührle collection due to statutes of limitations.

Stuart Eizenstat, the US secretary of state's special advisor on Holocaust issues, said during the announcement of the best practices in March that it was estimated "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".

Up to his death in 1956, Bührle amassed a collection of about 600 artworks. A large number of these are managed by the Bührle Foundation and have been on display at the Kunsthaus as part of a 20-year loan.

The rest are said to hang in the homes of Bührle's surviving relatives.