British historian David Irving has appeared in court in handcuffs, saying he would admit having denied the Holocaust in 1989 even though he no longer holds that view.
Asked whether he would enter a guilty plea before the three-judge panel, Irving told reporters moments before the formal proceedings began, "I have no choice".
Irving, wearing a blue suit, said as he entered the Vienna courtroom it was "ridiculous for me to be standing here on trial for something I expressed 17 years ago".
"I am not a Holocaust denier," he said.
"My views have changed. History is a constantly growing tree. The more you learn, the more documents are available, the more you learn, and I have learned a lot since 1989."
Asked about the Holocaust, he said: "I would call it the Jewish tragedy in World War II".
His handcuffs were removed as the trial began.
Irving is "everything other than a historian," the prosecutor told the eight-member jury.
Irving had painted "a new history ... a picture in which there are no gas chambers," he said.
Irving, 67, faces a 10-year prison sentence under an Austrian law that prosecutes those who "deny the genocide by the National Socialists or other National Socialist crimes against humanity".
The right-wing historian was arrested in November after a routine check on a highway in Austria.
The warrant for his arrest was issued by a Vienna court in 1989 after he allegedly denied at meetings in Austria that the Nazi regime used gas chambers in concentration camps.
The Holocaust was Nazi Germany's systematic slaughter of some six million Jews, mainly in the later years of World War II.
Irving has become notorious worldwide for attempting to establish, despite overwhelming evidence to the contrary, that Hitler was not party to the Holocaust, that there were no gas chambers in Auschwitz, and that the number of Jews killed by the Nazis was wildly exaggerated.
He has been condemned by the courts several times, notably in Britain and Germany, and last year he was refused entry to New Zealand.
He is reportedly also banned from residing in Australia, Canada, Italy and South Africa as well as Germany.
Irving sparked widespread outrage with his book Hitler's War in 1977, in which he claimed the Nazi dictator did not know about the mass killings of Jews until 1943 and that he never ordered the Holocaust.
In 2000, Irving lost a high-profile libel case in London against US historian Deborah Lipstadt, who called him a "Holocaust denier" in her book, Denying the Holocaust: The Growing Assault on Truth and Memory.
- AFP