BERN (REUTERS) - This is the so-called "degenerate" modern art the Nazis did not want people to see.

And this is the first time it is been on public display since it was seized from German museums.

The artworks are from a massive trove amassed by collector Hildebrand Gurlitt, who was enlisted by the Nazis to sell the works.

His son, Cornelius, inherited the collection and when he died in 2014 he stunned the Kunst Museum Bern by naming it the sole heir to all 1,500 works.

The museum in Switzerland's capital has now put together this exhibition, Degenerate Art - Confiscated and Sold, amid lingering questions about the collection's origins.

The museum's director Nina Zimmer says they have taken a cautious approach.

Says Zimmer: "To be totally sure, we have only took in our possession one third of the works in this exhibition where we are a 100 percent sure it's not looted, and the other two thirds, we are waiting for like final little details to clarify their status, and we currently don't see any suspicion of any such exceptional cases of looted art within this group of works."

German tax inspectors confiscated Cornelius Gurlitt's trove of artworks during a tax evasion probe, but it was returned to him when he agreed to cooperate with authorities investigating the work's provenance.

Some 150 artworks make up the Swiss exhibition including pieces from leading German artists of the 1920s and 30s that Adolf Hitler banned.
The museum believes it gives people the chance to have a close look at Nazi politics towards art and artists.

A separate exhibition of works from the collection will open in Germany.