The authenticity of the Trawniki card was affirmed by US government experts who examined the original document as well as by Wolfgang Scheffler of the Free University of Berlin during the hearing, Scheffler also testified to the crimes committed by Trawniki men and that it was possible that Demjanjuk had been moved between Sobibor and Treblinka. Additionally, the former paymaster at Trawniki, Heinrich Schaefer, stated in a deposition that such cards were standard issue at Trawniki. Five Holocaust survivors from Treblinka identified Demjanjuk as having been at Treblinka and having been "Ivan the Terrible." Additionally, OSI submitted the testimony of former SS guard Horn identifying Demjanjuk as having been at Treblinka. Although Demjanjuk's Trawniki card only documented that he had been at Sobibor, the prosecution argued that he could have shuttled between the camps and that Treblinka had been omitted due to administrative sloppiness. During the trial, Demjanjuk admitted to having lied on his US visa application but claimed that it was out of fear of being returned to the Soviet Union and denied having been a concentration camp guard. Demjanjuk instead claimed to have been a German prisoner who completed forced labor. The defense also submitted the statement of Feodor Fedorenko, a Ukrainian guard at Treblinka, which stated that Fedorenko could not recall having seen Demjanjuk at Treblinka. Demjanjuk's citizenship was revoked for having lied about his past in 1981, with the judge persuaded especially by the testimony of Otto Horn. Demjanjuk subsequently requested political asylum in the United States rather than deportation. His application for asylum was denied on 31 May 1984.