WASHINGTON -- John Demjanjuk, the retired auto worker wrongly convicted of being Ivan the Terrible, a brutal torturer in a Nazi death camp, is on trial again in Cleveland as the U.S. government seeks to strip him of his citizenship.

Two decades after Washington first revoked his citizenship and extradited him to Israel, Mr. Demjanjuk is accused of lying on his original visa application and concealing his past as a guard at several Nazi concentration camps. But once again, the defence is arguing that the prosecution's case is one of mistaken identity.

"Either the government's history is right or the defendant's is," said Edward Stutman, the U.S. Justice Department's prosecutor. The case is based on seven Second World War documents, which the government says prove that Mr. Demjanjuk was a Nazi camp guard.

Defence lawyers say that Mr. Demjanjuk is facing a "trial by archive," and that neither evidence nor witnesses have shown that he was a concentration-camp guard.

"We will show the court a scenario that explains how the government, once again, has got it wrong," defence lawyer Michael Tigar said. "After 22 years, the odyssey of John Demjanjuk is about to come to an end."

Joel Ratner, regional director of the Anti-Defamation League, said it was "important that those who participated in the Holocaust and then came into this country under false pretenses" be called to account. He was in the courtroom yesterday.

He acknowledged that "there are people in Cleveland who feel differently" and "even people in the Jewish community who feel differently," but said the ADL believes the government has a duty to uphold its laws.

The trial is expected to last two weeks. It remains unclear whether Mr. Demjanjuk, who has yet to appear in the courtroom, will testify. Even if he is convicted, appeals could drag the process out for years.

Mr. Demjanjuk, 81, is both physically and mentally unwell, according to his family. Yet he could face deportation to Ukraine, half a century after he left war-ravaged Eastern Europe for a new life in the United States. He became a naturalized U.S. citizen in 1958, changed his first name from Ivan and worked for decades in the auto industry.

In this trial, prosecutors will attempt to prove that Mr. Demjanjuk lied on his application for a work visa in 1951.

Prosecutors now accept that Mr. Demjanjuk was not Ivan the Terrible, a claim they successfully made two decades ago when he was extradited to Israel and tried for crimes against humanity.

His televised "trial of the century," as it was billed at the time, created an international sensation. Jewish survivors of the Treblinka extermination camp identified him in court as Ivan the Terrible, the evil guard who had whipped and tortured helpless inmates before they were gassed. Not since the 1961 trial of Holocaust architect Adolf Eichmann had a war-crimes trial created such a furor.

In 1993, Israel's Supreme Court freed Mr. Demjanjuk, after he had spent seven years in jail. With the collapse of the Soviet Union, evidence and documents emerged that strongly suggested another man, Ivan Marchenko, was Ivan the Terrible.

Although Mr. Demjanjuk no longer speaks publicly about his case, his family and supporters -- many of them in Cleveland's Ukrainian community -- contend that he has been victimized and impoverished by decades of persecution by the U.S. government.

Others paint an even darker picture, suggesting that far from a case of mistaken identity, Mr. Demjanjuk's case was a "deliberate and cold-blooded conspiracy," by the United States, Israel, Poland and the Soviet Union, to withhold exculpatory evidence.

Yoram Sheftel, who headed Mr. Demjanjuk's defence team in Israel, subsequently contended in a book about the case that the U.S. Office of Special Investigations not only suppressed evidence, but destroyed it in its desperation to win.

Although Israel's Supreme Court overturned Mr. Demjanjuk's conviction, it also rejected his claim that he spent most of the war in a German prisoner-of-war camp after being captured in the Crimea. Mr. Demjanjuk, who has offered different versions of his war years, has said that he was conscripted into the Soviet army and that he lied to avoid being sent back to the Soviet Union.