MUNICH (AP) -- An attorney asked a court to suspend John Demjanjuk's trial on Nazi war crimes charges Wednesday after presenting judges with an Associated Press story that uncovered documents showing the FBI believed a key piece of evidence was fake.

A newly declassified FBI field office report from 1985 casts doubt on the authenticity of a Nazi ID card showing that Demjanjuk served as a guard at the Sobibor death camp.

Defense attorney Ulrich Busch gave AP’s story from Tuesday to the judges as the trial resumed, saying he needed more time to investigate whether more such material could be found.

Busch said he needed the trial to be postponed so that he could go to the U.S. himself to look through Demjanjuk material held at the National Archives in Maryland, where the AP found the report.

The story shows “prosecutors did not introduce all the possibly exculpatory evidence from the United States here,” Busch told the court. The judges made no immediate ruling on the request.

Ukrainian-born Demjanjuk, a 90-year-old retired Clevelandautoworker, is accused of 28,060 counts of accessory to murder on allegations he served as a guard at Sobibor. Demjanjuk rejects the charges.

Claims that the card and other evidence against Demjanjuk are Soviet forgeries have repeatedly been made by Demjanjuk’s defense attorneys. But the FBI report provides the first known confirmation that American investigators had similar doubts.

Prosecutor Hans-Joachim Lutz told the court, however, that at the time of the FBI report the identity card had not been turned over to Western investigators, but that it has subsequently been examined by several experts, all of whom have declared it to be genuine.

He said that after the AP story the U.S. Justice Department contacted him saying that he had been shown the FBI report as part of two discs of scanned confidential documents that were made available at the U.S. Consulate in Munich. Still, he told the judges he did not recall ever having seen the report before but did not consider it important to the case.

Closing arguments were under way in the trial, which began in November 2009, and a verdict is expected next month.