The descendants of Raoul Wallenberg, the Swedish diplomat who saved thousands of Jews from the Nazis during World War II, are suing Russia’s Federal Security Service (FSB), the Interfax news agency reports.

In their claim, filed with a Moscow District Court, Wallenberg’s family demands the Russian security services provide full and uncensored access to original documents in the case.

“Despite the huge number of inquiries and appeals that relatives and historians sent to Russian state bodies over the past decades, Russia still refuses to provide originals of the documents,” lawyer Ivan Pavlov, who represents the family, was cited as saying.

The Russian government has in the past given some documents related to Wallenberg’s case, but they were often incomplete and censored. In March, the family sent a request to the FSB for access to original documents, but they received no answer.

“Our search for answers to questions about the fate of Raoul Wallenberg will continue as long as we do not know what happened to him and why,” Wallenberg’s niece, Marie Dupuy, was cited as saying in the report.