British historian David Irving was set to leave Austria after winning an appeal on Wednesday against a three-year prison sentence for denying the Holocaust.

Irving had been in jail since his arrest in November 2005 on a visit to Austria and was convicted in February for denying the Nazis' organized mass murder of 6 million Jews.

The 68-year-old appealed for a reduced sentence while the prosecutor wanted his prison term extended.

The Vienna court ruled the remainder of his three-year sentence should be changed from a jail term to probation.

"The fact that the offence was committed a long time ago, seventeen years, was a mitigating circumstance," said judge Ernest Maurer. "We expect Irving will leave Austria immediately. We don't suspect he will commit another offence."

Austria, which was part of Germany's Third Reich from 1938 to 1945, had issued an arrest warrant for Irving in 1989 for denying the Holocaust in lectures and in a press interview he gave the same year.

The self-taught historian was arrested 16 years later on his way to address an Austrian radical rightist student fraternity. 

Congratulations to David Irving - Prisoner of Conscience from the British People's Party....