In 2012, authorities in Bavaria investigating a tax dispute stumbled on one of the most significant unknown collections of 20th century art in the possession of an eccentric recluse, Cornelius Gurlitt.
The paintings – including masterpieces by Chagall, Picasso, Monet and Renoir – had an ugly past. Mr. Gurlitt's father was one of four art dealers given responsibility for handling works stolen or confiscated by the Nazi regime. The Nazis looted paintings from Jewish families and removed works they considered undesirable from German museums.
Now the paintings have a new home in a Swiss museum. On Monday, at a press conference in Berlin, the Kunstmuseum Bern announced that it would accept the collection as Mr. Gurlitt had instructed in his will (he died in May). But under an agreement with German authorities, the artworks will not leave the country until it is clear that they were not stolen from their rightful owners.
"Looted art and art which is suspected to be looted art … will not even make it onto Swiss territory," said Christoph Schaeublin, chair of the Swiss museum's foundation board, on Monday. He added that the decision to accept the collection was "far from easy."
The agreement reached between the Swiss museum, the German federal government and the Bavarian state government pledges to handle the process in a transparent manner. As a first step, a list of the more than 1,200 artworks in the collection is expected to be made public within days. Nearly half the total is suspected of having been being looted by the Nazis.
Moves toward greater openness are badly needed. At first, authorities in Bavaria did not announce what they had found in Mr. Gurlitt's apartment. And families of those with claims on the art say German authorities have dragged their feet about researching the paintings' origin, prompting some to launch court proceedings. In early November, Ronald Lauder, the president of the World Jewish Congress, said the Kunstmuseum Bern risked an "avalanche" of lawsuits if it accepted the art collection.
In addition to pieces stolen from Jewish families, the collection also includes works of so-called "degenerate" art confiscated from German museums under a law passed by the Nazis in 1938. Some of those museums would dearly like those paintings back, opening another potential front in the legal fight over the artworks.
The focus on Mr. Gurlitt's collection stirs up uncomfortable questions. Only a third of Germany's museums have researched whether their collections contain art looted by the Nazis from Jewish families, said Anne Webber, who chairs the London-based Commission for Looted Art in Europe, in a recent interview with Deutsche Welle.
"There still seems to be a huge reluctance in Germany to appreciate the moral and ethical significance of holding on to looted works of art," Ms. Webber told the German broadcaster. "It would be dismaying if museums were now to focus their efforts on restoring their own collections rather than on returning the looted art in their possession."
Some have been even more scathing in their criticism. Alfred Weidinger, deputy director of the Belvedere museum in Vienna, recently castigated Germany for failing to write a law on how to restore tainted artworks to their original owners.
"In Germany they are clearly trying to sit it out until all the Holocaust victims have died, until no more claims are made, until everything has been forgotten and consigned to the past," said Mr. Weidinger earlier this month in an interview with The Art Newspaper.
In October, the German government announced it would fund the creation of a new Center for Lost Cultural Assets. Its responsibility is to coordinate and expand efforts to research the provenance of works stolen by the Nazis.
For some, like Mr. Weidinger, even provenance research will not free the Gurlitt collection of its stained reputation. In the November interview, he called upon the Kunstmuseum Bern to sell the collection in its entirety and devote the proceeds to an institution caring for Holocaust victims.
"These works are fundamentally tainted. They are linked with the name Gurlitt and that is a problem," he said. "You will never have a 100 per cent guarantee that everything is really all right."