BERLIN—German museums are coming under growing international pressure to provide digital access to their full collections, in the wake of the discovery of a suspected plundered art trove in Munich that authorities kept secret for nearly two years. Under international norms adopted in Washington in 1998, German museums are obligated to go through their collections for works that may have been looted by the Nazis. But the museums have balked at going a step further and digitizing their collections to allow independent searches, citing budget restrictions and a lack of staff. That reluctance has for years been a source of tension within the art world, with critics alleging other motives. "They don't want to let people see what they have because they know if they put it online they'll get claims and possibly lose major paintings," Ronald Lauder, a billionaire art collector and president of the World Jewish Congress, said in an interview.

The man who walked into the police station with me on the 15th of August, delivering two works by Schoonhoven, is still imprisoned, waiting trial. The other day he called me to give me an update. 

According to him, he bought the two works in an official shop. The police went to the shop and interrogated the owner, who denies having sold the artworks. The shop owner stated that this particular kind of receipt was not even used by him. But, in the pretrial, the defense attorney noted that the receipt was signed with a signature that was identical with the shop owner's signature on his statement. 

The defense attorney also asked the judge to hear the director of Sotheby's, the Netherlands, which was granted. Sotheby's had auctioned one of the stolen artworks. Why did Sotheby's not withdraw the artwork after a warning from the ALR that it might be a work stolen three months before, a theft that made headlines? If, according to the lawyer, even the experts at Sotheby's missed it, how could his own client possibly have known that the works were stolen? 

And maybe the most interesting question of all: Why did Sotheby's turn the work 90 degrees before depicting it in their catalogue? 

Anyway, the plot thickens and there might be some surprises left.

Art forgery has been a hot topic lately since the disclosure that Pei-Shen Qian, a 73-year-old immigrant from China, working out of his home in Queens, reportedly created at least 63 drawings and paintings by Jackson Pollock, Robert Motherwell, Barnett Newman, Franz Kline, and Richard Diebenkorn.

The works were sold or consigned by Glafira Rosales, a dealer of Sands Point, New York, to two Manhattan dealers, Knoedler & Company, which closed in 2011, and Julian Weissman. Over a period of 15 years, the works were sold to collectors for about $80 million. Knoedler, its former president Ann Freedman, and Weissman have consistently stated that they were convinced that the works were authentic. Freedman says she showed the paintings to a number of experts, who confirmed the authenticity and quality of the works. 

The case against Rosales is known as United States of America v. Glafira Rosales, a/k/a “Glafira Gonzalez,” a/k/a “Glafira Rosales Rojas,” defendant. She pleaded guilty in September to charges of wire fraud, money laundering, and tax evasion. As we went to press, no one else had been charged in the case, but Assistant United States Attorney Jason P. Hernandez indicated that additional arrests were contemplated.

Augsburg prosecutor Reinhard Nemetz said in a statement on Tuesday that artwork that was not suspicious, not stolen by the Nazis and "undoubtedly was the property of the accused" would be returned to Gurlitt "immediately." 

"It is of key importance that works taken in connection with the Nazi persecution be identified so that outstanding property claims can be settled and possible previous owners can exercise their rights," said Nemetz.

As scientific director of a task force, he is responsible for shedding light on the darkness of a case which has been followed by art lovers around the world for the past two weeks -- the seizure of hundreds of paintings, drawings and etchings from the home of Cornelius Gurlitt, some of which may be art that had been looted by the Nazis. The collection had belonged to his father Hildebrand Gurlitt, who had collaborated with the Nazis after 1933. 

Earlier this month, Hartmann already publicly stated his own position about the art. "In many cases, we're not dealing with art looted by the Nazis," he told the German news agency DPA. "We must therefore act on the assumption Mr. Gurlitt is lawfully in possession of this property." 

Hartmann is charged with pulling the chestnuts out of the fire for the public prosecutors in Augsburg, who seized Gurlitt's art collection at the end of February 2012 on a very questionable legal basis. But his work will also be on behalf of the Bavarian state government and officials at the Finance Ministry in Berlin who were informed of the sensational discovery but said and did nothing about it -- and Germany itself.

Hartmann is to act as academic head of the task force. Alongside Hoffman, five other art historians will be hired temporarily or borrowed from museums. The Bavarian representatives want these art experts to have a public prosecutor at their side, as well. The exact identities of the other members of the task force, however, shall remain secret. That, of course, will leave less room for the transparency Westerwelle has demanded. 

Berggreen-Merkel announced as a first measure that the public prosecutor's office in Augsburg will publish images of 576 paintings which are suspected to be looted art at www.lostart.de as soon as possible. But prosecutors must still determine the legal basis for releasing the images on the Internet given that Gurlitt hasn't been accused of committing any crime.

But it is unlikely the researchers will be able to act with the urgency required. At the annual meeting of the Provenance Research Working Group last week in Hamburg, the around 60 attendees spoke of "undertaking the requisite research into the Munich art find as speedily as possible, but also in the necessary scientific quality." 

The working group has existed for 10 years, but its members have not been able to agree on a standard for provenance specifications. It's more likely it will take the task force years rather than months to identifiy possible looted art in Gurlitt's collection. "Each case is unique," said one provenance researcher, "every picture is different."

At first, it also appeared that politicians and officials in Berlin were hesitant to include members of the Jewish Claims Conference among the experts reviewing the Gurlitt collection. With pressure growing, however, officials announced Monday that 10 experts would be part of the group probing the artworks, including two researchers with the organization, which has sought the return or restitution of Jewish property lost during the Holocaust. 

"The Claims Conference has represented the interests of Jews persecuted by the Nazis for more than six decades in all questions about damages and restitution," Rüdiger Mahlo, the international organization's German representative, said last week. "It is self-explanatory that there should be representation of the Jewish victims on such a commission." 

While the task force is being created, investigators in Augsburg are still receiving inquiries from lawyers who want to know whether artworks they are looking for on behalf of the heirs to the victims have been found in Gurlitt's apartment. Some 100 lawyers have already registered their interest with the public prosecutor's office. They have not received any answers.

Hans Christoph's 'Couple' 1924 TELEGRAPH

Almost a year before his death, Hildebrand Gurlitt (1895-1956) wrote a six-page essay on the history of his collection that was originally intended to serve as a foreword for an exhibition catalogue. But it was never printed "for all kinds of reasons," as Gurlitt wrote in a letter in November 1955. This forgotten manuscript, which was kept for decades in the Düsseldorf city archives, is one of the few texts written by Gurlitt that provides an insight into the life and intellectual world of this passionate collector. One page -- in which Gurlitt apparently describes his career as an art dealer during the Nazi era -- is missing from the archives. Nevertheless, the surviving pages are an important source of information on the life of this man. The following is a compilation of the key passages:

A great many works of modern art passed through my hands. They came from painters, from emigrated clients and friends, from people who preferred to sell the paintings as a precaution, from the depot of confiscated art in Niederschönhausen where, if you had enough pluck, you could buy very beautiful paintings with the same foreign currencies that were otherwise illegal to possess and could land you in jail. What wasn't sold for cash -- some 80,000 works of art, I believe -- was burned by the SS. I was able to save many of these paintings from destruction and pass them on to great collectors, like Josef Haubrich in Cologne and Bernhard Sprengel in Hanover, who purchased the entire collection of prints and drawings by Emil Nolde. There were always men whose profound love of the new art made them courageous, but everything was done half in secret.

(A page is missing here.)

(After the bombing raids on Dresden on the night of Feb. 14, 1945 -editor's note) we swore to regret no material losses, to recognize the logical consequences that had led to the destruction and, although we were filled with sorrow, to resume life, no matter how simple.

I found the safeguarded remains of the collection and still own them. But their adventures had actually only just begun. Torn from their passepartouts, dispersed at various locations, part of the collection was in Saxony, and it was only later, after a communist village mayor had confiscated them, that I was able to secure their release with a bit of cunning and, thanks to a good Russian who was delighted with two bottles of schnapps on a rainy night, slip them through the Iron Curtain. Another part of the collection was confiscated by the Americans and returned to me -- safe and sound -- by an outstanding specialist five years later. A third part of the collection was hidden in the thick walls of an old windmill in the Franconia region and later recovered.

I have not been an art dealer for many years now; the "thousand years" of the Third Reich were enough for me. But I won't sell any of these works of art, just as I can acquire very few new ones. I see this collection, which has -- quite unexpectedly, I must say -- fallen back into my hands after so many perils, not as my property, but rather as a kind of fief that I have been assigned to steward.

According to the Bavarian justice ministry, some 1,280 paintings and drawings were found in the apartment, although a figure of more than 1,400 works had been mentioned previously. The collection can be roughly divided into three groups:

• First, there were the pictures that Hildebrand Gurlitt sold on behalf of the Nazi dictatorship, which it classified as "degenerate" and which he was expected to turn in hard currency abroad. The Bavarian investigators estimate that this category includes 380 works of art.

• The second group consists of those works that were "seized in connection with acts of persecution," or the so-called looted art. These are works that were stolen from their Jewish owners. The Nazis confiscated entire collections, forcing Jewish collectors into selling them their artworks. Top Nazi officials obtained some of the works, while others ended up with art dealers. Cornelius Gurlitt's collection apparently contained some 590 works that officials suspect may have been looted art.

• The third group, which includes 310 artworks, appears to be more innocuous. Hildebrand Gurlitt's acquisition of some of the pieces may be above suspicion, perhaps because he purchased them before the Nazi era or because they were part of the family estate.

Meanwhile, Gurlitt was expected to sit in a corner and remain quiet. He complied with their wishes, watching as they removed Max Liebermann's "Two Riders on the Beach" from the wall, a work that had hung there for decades, and took the Chagall from the locked wooden cabinet. 

They left nothing behind, not even the small suitcase containing his favorite pictures, a collection of works on paper. For decades, Gurlitt had unpacked the drawings each evening to admire them. Now they were gone and Gurlitt was alone.

Since that day, Gurlitt has been alone in his bare apartment, in a white-painted building in Munich, a city he calls a prison. And ever since the German newsweekly Focus uncovered the confiscation of his collection two weeks ago, the world's press has been gathering downstairs, outside the front door of his apartment block. Whenever he leaves the building, he is inundated with camera flashes, as if he were a war criminal. Strangers are constantly knocking on his door and sliding letters through the mail slot. 

The works are a sensational treasure trove, including paintings by Marc Chagall, Max Beckmann, Franz Marc, Pablo Picasso and Henri Matisse. The mysterious collection stems from the estate of his father, Hildebrand Gurlitt, an art critic, museum director and art dealer who died in 1956, one of the men who established modern art in Germany and, after 1933, did business with the Nazis. 

The family moved around a lot, always following a father who didn't have an easy time because he "wasn't racially flawless," Gurlitt notes. But he always fought and was very clever, he adds. In Hamburg his father registered the art gallery at Klopstockstrasse 35 in his wife's name, with the art dealer himself listed as an employee. Later, in Dresden, Gurlitt says his father didn't register his business at all. Instead, he kept the works of art at home and ran his business from there. "My father was often driven out, he often fell but he always got back up on his feet again."

He remembers playing among paintings by Liebermann, Beckmann and Chagall when he was a child. They moved with him from city to city, and hung in the living rooms and hallways. His father sorted them and loved them -- and they all bear his mark. He hung the green face by Ernst Ludwig Kirchner on the wall above young Cornelius' bed. "Hitler didn't like green faces," says Gurlitt. In the privacy of their home, the family didn't speak well of the Führer, Gurlitt recalls. His father resisted the dictator, but so surreptitiously that no one noticed it, he adds. 

Hildebrand Gurlitt never bought anything from a private individual, Cornelius insists. Anything else would have been unimaginable for him. The pictures came from German museums or art dealers, Gurlitt says, adding that his father only cooperated with the Nazis because he wanted to save the paintings from being burned. And then he says: "It's possible that my father may have been offered something privately, but he certainly didn't accept it. He would have found that unsavory."

He helped his father back in Dresden when they saved the works of art from the Russians. People should be thankful to him, he says. "My father knew the Russians were getting closer and closer." 

His father quickly organized a vehicle from the carpool in Dresden, he recalls, and father and son loaded the artwork into the car. His father then brought everything to a farmer near Dresden, and later to a castle in southern Germany. He says that his father knew people everywhere in Germany.

Gurlitt sees his paintings in the newspapers. He's appalled. "What kind of state is this that puts my private property on display?" he asks. Gurlitt has tears in his eyes. He whispers: "They have to come back to me." 

The next morning, Bavarian Justice Minister Winfried Bausback is quoted in the newspaper as saying that the authorities should definitely speak with Gurlitt. 

It's painful to see Gurlitt being slowly consumed by despair. "They have it all wrong," he says. "I won't speak with them, and I won't voluntarily give back anything, no, no. The public prosecutor has enough that exonerates me." 

Gurlitt hopes the paintings that are rightfully his will soon be returned. He would still like to sell one work, though, perhaps the Liebermann -- if he is entitled to it, as he puts it -- to pay his hospital bills. The remaining paintings should be returned to his apartment, he says. The Chagall will then be put back into the cupboard, and the painting of the woman playing the piano will go in the hallway, where his mother always hung it. 

"I've really missed the paintings -- I notice that now." He says there has been enough public exposure -- of him and his paintings -- and he won't give them to any museum in the world. They have enough other things that they can exhibit, he contends. 

"When I'm dead, they can do with them what they want." But until then, he wants to have them for himself. Then he'll finally have a bit of "peace and quiet" again.