"This is one of our last chances to inject a new sense of justice into this issue before it's too late for Holocaust victims," said Stuart Eizenstat, head of the U.S. delegation to the conference and a former ambassador and deputy Treasury secretary during the Clinton administration.
The Holocaust Era Assets Conference, hosted by the Czech Republic, is an attempt to revive a global campaign that began 11 years ago to track down long-lost art collections that were confiscated or acquired under dubious circumstances during the Holocaust.
In December 1998, after many world-famous museums were found to have Nazi-tainted art in their collections, representatives from 44 countries met in Washington and endorsed guidelines for investigating claims of stolen items and returning them to their rightful owners.
The guidelines, known in the art world as the Washington Principles, have eased the return of looted art in many cases. Despite their endorsement by most European countries and the United States, however, the guidelines are legally nonbinding. They are also often ignored in practice by museums and governments that profess in public to abide by them, according to art experts.
Michal Klepetar, a real-estate project manager from Prague, has been trying for nine years to persuade the Czech National Gallery to relinquish 43 paintings that once belonged to his great-uncle, Richard Popper, a prominent collector who was deported to Poland and perished in the Jewish ghetto in the city of Lodz.
Popper's wife and daughter also died in Nazi camps. Klepetar, 62, and his brother are their closest living relatives. But the National Gallery has refused to part with the paintings, citing a law adopted in 2000 by the Czech government that entitles only Holocaust victims or their "direct descendants" to file claims for stolen property.
In an interview, Klepetar argued that the Czech law was unconstitutional, unethical and particularly unfair to Jews. An estimated 6 million Jews were killed in the Holocaust; many families were survived only by distant relatives.
"This country, like most of the region, had always been anti-Semitic through the centuries," he said. "The only difference now is that it's not politically correct. That's the root of the whole problem."
Klepetar's great-uncle had amassed a collection of 127 artworks -- mostly Flemish and Dutch paintings from the 17th and 18th centuries -- which vanished after the war. In 2000, however, Klepetar said someone leaked him part of a confidential Czech government report on looted art that indicated 43 of the paintings had been in the National Gallery's possession since the early 1950s.
The National Gallery later acknowledged it had the paintings but refused to divulge any details, such as how they were acquired, their condition or their precise location. Klepetar has pressed his claim in the Czech courts for several years but has lost repeatedly because he is not considered a direct descendant under the law.
Tomas Jelinek, vice president of the Czech Committee for Nazi Victims, said the government's decision to pass the 2000 law that limits who can file claims for Holocaust assets was designed to protect public galleries and government institutions.
"You have all these people in charge of the museums, and they don't want to lose their assets," he said. "There are always people who say, 'Why should we give these valuable objects from our collections away?' "
Tomas Wiesner, director of galleries and museums for the Czech Ministry of Culture, did not respond to requests for comment.
Art experts credited the Czech government with taking steps to make it easier to find and return looted art. In 2001, for instance, it established the Documentation Center for Property Transfers of Cultural Assets of World War II Victims, which maintains a public online database of artworks in Czech museums that once may have been owned by Holocaust victims.
The database, however, offers limited information and is hampered by spotty recordkeeping. For example, it lists only eight of the 43 paintings in the National Gallery that were part of Klepetar's family collection, even though the museum has acknowledged it has the others as well.
The Documentation Center also does not publish statistics on how many claims have been filed on behalf of Holocaust victims, or how many artworks have been returned. Helena Krajcova, director of the center and co-chair of the looted-art panel for the Holocaust Era Assets Conference, did not respond to requests for an interview.
Czech officials have sometimes taken extraordinary legal measures to prevent the return of looted art.
In December, the American heirs of Emil Freund, a Prague lawyer and collector who was killed during the Holocaust, reacquired 32 paintings and drawings that had been in the custody of the National Gallery for decades. But the Ministry of Culture classified 13 of the looted artworks as cultural treasures, a designation that prevents them from being taken out of the country.
Michaela Sidenberg, curator for visual art at the Jewish Museum in Prague, a private institution, said Holocaust survivors and their families are repeatedly stonewalled in the Czech Republic, despite official policy to make it simple for them to file claims for artwork taken by the Nazis.
"It's like a hot potato being thrown around," she said. "The claimants are kicked around from one bureaucracy to another. Everybody is just looking for some alibi and to avoid taking responsibility."
Asked about such criticism, Stefan Fule, the Czech Republic's minister for European Union affairs, said his government's hosting of the conference on Holocaust-era assets demonstrates its dedication to resolving such claims fairly.
"These are serious questions that need to be seriously addressed," he said at a news briefing Friday. He declined to say, however, whether the Czech government would consider changing its laws so that distant relatives would be allowed to inherit property stolen by the Nazis.
In the meantime, Klepetar said he will keep pressing his case for the return of his great-uncle's collection, even though he predicted that there was "almost zero" chance that the Czech government would change its laws or policies.
"No, no, I'm not going to give up," he said. "It's the principle. Like they say, a Jew should never let anyone [defecate] on his head. And you can quote that."