Attorneys for John Demjanjuk want an American court in Cleveland to set aside the ruling that led to his deportation to Germany and his conviction on Nazi war crimes charges.
The request for a new hearing on the retired autoworker's denaturalization could bring the decades-old case back to the United States.
Demjanjuk's attorneys charge that the government failed to disclose important evidence, namely a 1985 secret FBI report uncovered by The Associated Press that indicates the FBI believed a Nazi ID card purportedly showing Demjanjuk served as a death camp guard was a Soviet-made fake.
"The government has kept these materials hidden from view," according to the motion filed Tuesday in U.S. District Court in Cleveland.
Demjanjuk, 91, was convicted in a German court on May 12 of 28,060 counts of accessory to murder, finding that he served as a guard at the Nazi's Sobibor death camp in occupied Poland. He was sentenced to five years in prison.
Ukrainian-born Demjanjuk was a Soviet Red Army soldier captured by the Germans in 1942. The Munich court found he agreed to serve the Nazis as a guard at Sobibor.
Demjanjuk denies serving as a guard at any camp and is currently free pending his appeal. He's been in poor health for years and has been in and out of a hospital since his conviction.
He currently cannot leave Germany because he has no passport, but he could get a U.S. passport if the denaturalization ruling is overturned.
A message seeking comment was left with federal prosecutors on Wednesday.
A federal judge in Cleveland opened the door for the new challenge in May by appointing a public defender to represent Demjanjuk and indicating that he could revive his U.S. denaturalization case based on the 1985 FBI report.
"It is the responsibility of the court to insure the integrity of court proceedings," said the order from U.S. District Court Judge Dan Polster. "There has already been one confirmed instance of fraud against the court in the first denaturalization trial."
But the judge also has said Demjanjuk must serve his sentence in Germany.
In a 1993 review of the American denaturalization hearing that led to Demjanjuk's extradition to Israel, a U.S. appeals panel concluded that the U.S. Justice Department's Nazi-hunting unit engaged in "prosecutorial misconduct that seriously misled the court" by withholding evidence.
"How is it, then, that especially after a finding of fraud on the court for failure to disclose key information about the true identity of Mr. Demjanjuk, the government still failed to turn over to the defense a recently declassified March 4, 1985 memorandum," Demjanjuk's attorneys said in the motion for a new hearing on the denaturalization.
Demjanjuk's defense attorneys have repeatedly claimed that the card and other evidence against him are Soviet forgeries. The FBI report provided the first known confirmation that American investigators had similar doubts.
In three decades of U.S. hearings, an extradition, a death sentence followed by acquittal in Israel, a deportation and the German trial, the arguments have relied heavily on the photo ID from an SS training camp.
During the most recent trial, the German court rejected a defense request to suspend the trial so that defense attorneys could travel to the U.S. to examine the new material.