Nazi art: does Germany have a problem returning art stolen by the Nazis? Marinello is referring to the discovery of 1,500 works of art, including Picassos, Matisses and Klees, found crammed into the back room of a Munich apartment, among tins of food and packets of noodles; a place belonging to the son of the man charged with selling off the works from the Degenerate Art exhibition. An apartment building in Munich where it is believed that German customs discovered missing artworks While this discovery has been described as "the greatest art find of the post-war era" (its probable value is in excess of £1 billion) its full significance cannot be gauged as a list of the works has yet to be published. If the way in which this hoard was discovered is extraordinary - Cornelius Gurlitt, son of the prominent Munich art dealer Hildebrand Gurlitt, was apprehended by chance in a clampdown on tax-evaders - even more bizarre is the way the Bavarian authorities have held on to the information over the two and a half years since the works were first found. The matter only came to light through an accidental leak to the German news magazine Focus. The examination of the works had been put in the hands of an organisation called the Research Centre for Degenerate Art. Meanwhile, since his detention for tax evasion, but before the seizure of the collection, Gurlitt was able to sell a major work, Max Beckmann's The Lion Tamer, through a reputable dealer for €840,000 (£731,000). "You have to wonder what is behind the extreme reluctance to provide information," says Anne Webber, of the London-based Commission for Looted Art in Europe. We have reminded the Bavarian authorities of the need for transparency and requested a full list of the works. So far we have had no response. Germany was a signatory to the Washington Principles in 1998 and 1999, along with 44 other countries, making a commitment to identifying the looted works in their collections and publishing the results. Bavarian state collections contain thousands of works acquired during the Nazi period, but they have failed to publish any list. An annotated catalogue of one of the main dealers of the Nazi era was discovered, saying which families the works were taken from and their eventual owners. This would be fantastically useful to the families concerned who are hoping to create a link with their past. This also hasn't been published. It is tempting to see this apparent blocking by the Bavarian authorities as something more than the embarrassment that characterises Germany's official response to its 20th-century past: bloody-mindedness, perhaps, or even belligerence. Bavaria is synonymous, certainly from a British perspective, with social and political conservatism. Munich, though it was an avant garde stronghold early in the century - home to Klee and Kandinsky - provided the platform for Hitler's rise to power. You don't have to dig too far below the surface in this part of Germany to encounter an attitude of "what more do these Jews want from us." Yet this apparently wilful obfuscation regarding the return of looted works of art is far from exclusively Bavarian. Webber quotes culture minister Bernd Neumann, who declared recently that until the thousands of looted art works in German museums are returned to their owners, there can be no line drawn under this issue. Hanover's Sprengel Museum, for example, home of the largest collection of the works of Kurt Schwitters, one of the most notable of the banned "degenerate" artists, has yet to publish a list of contested works. The head of the German Museums Association recently went on record as saying that the reluctance to publish lists of works is tied to the likelihood of large numbers of claims. "That surely is the point," says Webber, with a laugh of exasperation. You publish the lists so that the rightful owners of the works have the opportunity to come forward. These are works of art that were stolen in the most appalling circumstances and museums were often complicit in the theft. Only 200 of the Munich works are believed to be on the Art Loss Register's list of missing masterpieces. That doesn't mean that the other 1,300 works aren't masterpieces, simply that nobody has laid claim to them, because the rightful owners don't know they exist. "If people see photographs of listed works, it may prompt memories of things that belonged to their relatives," Webber says. "The time this should have happened is yesterday," says Marinello, who is currently acting on behalf of French broadcaster Anne Sinclair, the former wife of Dominique Strauss-Kahn, the disgraced former head of the IMF, in a claim for a major Matisse painting from a Norwegian museum. People are dying, memories are fading, records are being lost, and the German authorities are holding on to this information. When people make claims for works of art, museums ask for a receipt of payment. When you're running for your life, the last thing you're thinking about is the receipts for paintings you've bought. Yet one can surely feel some sympathy for museum directors who might face losing substantial parts of their collections, seeing their institutions diminished and, conceivably, staff laid off. "They're curators," says Webber, "and it's the job of a curator to keep a collection together." Indeed, isn't there a value in keeping these works in the public domain? In 2006 Ernst Ludwig Kirchner's Street Scene, centrepiece of Berlin's Brücke Museum, devoted to the radical expressionist group, was returned to the family of its original owner. It was sold for $38 million (£24 million) and disappeared from public view. The public, who need to understand the place of art in history, were surely the poorer. "That is irrelevant," Marinello says. The original owners of these works have the right to do whatever they want with them. Their families were murdered, their culture was destroyed; the restitution of these works of art is a small recompense. And it's not about monetary value. There's an attitude even in certain sections of the British press that this is about rich Jews getting even more money. The German authorities are hanging on to the details of these works until they establish their financial value. But it doesn't matter if it's a Picasso worth £20 million or a work by an unknown artist worth £20, the principle is the same. It is apparently likely that most of the works in the Munich hoard were not part of the Degenerate Art collection - confiscated works that were sold off to buy Aryan masterpieces (Vermeer, Rembrandt and the like) for Hitler's Führer Museum - but are works seized from French Jews during the Occupation. Here we enter the territory of France's wartime collaboration. And beyond the holdings of museums lies the far more complex matter of paintings in private collections, which may have changed hands several times on the commercial art market over the decades since the Second World War. Europe, and not least Germany, has made massive strides in coming to terms with the legacy of the Nazi period and the Second World War, but the restitution of stolen art works is a relatively recent aspect of that process which did not really get under way until the 1990s. In that light, events such as the Degenerate Art exhibition feel painfully recent. From the point of view of art it will be a long time before the ghosts of the mid 20th century are finally laid to rest. IN PICTURES: The 10 most-wanted missing paintings