The timing could not have been more symbolic: days before Germany and the world marked the 60th anniversary of the Nuremberg trials of Nazi war criminals, Austria announced it had arrested Holocaust denier David Irving.

Mr Irving had hit the international headlines five years earlier, when he sued American historian Deborah Lipstadt for libel in Britain.
He lost and the court branded him "an active Holocaust denier".

Lyn Smith, a professor of politics in London, is bewildered by people like Mr Irving, who deny there were gas chambers at Auschwitz or that Hitler knew his underlings were systematically murdering six million Jews, plus millions more Slavs, Gypsies, Jehovah's Witnesses, homosexuals and political prisoners.

"That's something I just cannot understand - that people like Irving continue to deny, when there is so much evidence."

Mrs Smith is more familiar with the evidence than most.

Starting in the 1970s, she worked as an oral historian for London's Imperial War Museum, interviewing survivors of the Holocaust for the museum's sound archive.

She has recently assembled testimonies from the archive into an extraordinary book, Forgotten Voices Of The Holocaust.

'Near as you can get'

The book weaves together excerpts of recordings from survivors and witnesses, tracing the Holocaust chronologically, from the persecution that accompanied the rise of Hitler, through the ghettos, concentration camps and death camps, death marches, liberation and the aftermath.

"It is as near as you can possibly get to first-hand views of the Holocaust," Mrs Smith says.