Convicted Nazi war criminal John Demjanjuk’s bid to regain his U.S. citizenship was denied on Tuesday, The Associated Press reported.

According to the report, U.S. District Judge Dan Aaron Polster said Demjanjuk had lied about where he was during World War II.

Polster rejected the retired autoworker’s citizenship claim, which was based on newly discovered documents, including one suggesting an incriminating document was a Soviet fraud. The appeal by Demjanjuk’s attorneys was filed in November.

“John Demjanjuk has admitted that he willfully lied about his whereabouts during the war on his visa and immigration applications to gain entry to the United States,” the judge was quoted by AP as having written. “Despite numerous opportunities, Demjanjuk has never provided a single, consistent accounting of his whereabouts during the war years 1942 to 1945.”

Demjanjuk, a retired auto worker, was found guilty in a Munich court last May of assisting in the murder of more than 27,000 Jews at the Sobibor concentration camp while serving as a Nazi guard.

His attorneys then claimed that hundreds of pages of newly released documents cast doubt on the U.S. effort to revoke his American citizenship.

They charged that the government failed to disclose important evidence, including a 1985 secret FBI report uncovered by AP. The report indicates the FBI believed a Nazi ID card purportedly showing that Demjanjuk served as a death camp guard was a Soviet-made fake.

91-year-old Demjanjuk, who was sentenced to five years in prison by the German court,has been in poor health for years and has been in and out of a hospital since his conviction.

His public defender, Dennis Terez, would not comment on a possible appeal of the citizenship ruling but told AP, “We’re evaluating our various options at this point.”

Mike Tobin, a spokesman for the U.S. attorney’s office in Cleveland, told AP prosecutors were pleased with the ruling.

“All along the issue in this specific aspect of the case was really just the uninformed or misinformed speculation of one FBI agent, as I think the ruling makes clear,” he said.