THE twin brother of David Irving yesterday challenged the sincerity of the historian's claim that he now believes millions of Jews were killed by the Nazis and that gas chambers did exist.

John Irving is so unlike the right-wing historian and Holocaust denier that he serves as chairman of Wiltshire Racial Equality Council in England.

Asked about his brother's recantation before a Vienna court, John Irving said: ''If I said 'E pur si muove!' would it mean anything to you?''

The quotation is often attributed to Galileo, who was forced by the Inquisition in 1633 to retract his heretical belief that the Earth moves around the Sun.

The astronomer and philosopher was facing the death penalty but escaped with life imprisonment after disowning his findings. Under his breath, he is reputed to have murmured the now-famous Italian phrase meaning: ''Yet still it moves.''

David Irving denounced his previous denial of the Holocaust at the opening of his trial where he faced a maximum of 10 years' imprisonment under Austria's anti-Nazi laws.

The controversial historian was ruined when he sued Deborah Lipstadt for libel in London in 2000 after the American academic branded him ''one of the world's most prominent and dangerous Holocaust deniers''.

The judge in that case described Irving as ''an active Holocaust denier, anti-Semitic and racist'' who had ''distorted historical data to suit his own ideological agenda''.

Dr Lipstadt said yesterday that Irving's retraction was ''rubbish''. ''I wouldn't be the least surprised if, when he arrives back in London, he will say, 'The reason I said this was a get-out-of-jail-free card','' she said.

Unable to pay Penguin Books' costs, Irving was forced into bankruptcy and lost his home in London's Mayfair.

He now lives with his girlfriend, Bente Hogh, in a more modest, rented flat in Kensington, west London.

His books are sold through a website belonging to a publishing company run by Ms Hogh. Although he claims to have rejected his old views, he makes the full texts of his works available on the internet for free downloading.

Nuremberg: The Last Battle is filled with references to claims that Nazi gas-chamber atrocities were exaggerated by the Allies. Various versions of his book Hitler's War are freely published there too. His website hails ''the courageous Viennese students'' whose invitation to Austria resulted in his arrest. It claims that, while in prison, he has handwritten a 600-page autobiography, Irving's War.

Irving makes regular visits to the US, hosting the annual Real History, USA, festival in Cincinnati. Highlights have included a showing of Leni Reifenstahl's notorious propaganda film Triumph of the Will about Hitler's 1934 Nazi congress in Nuremberg.

His American opponents relish trying to disrupt his progress, telephoning hotels and restaurants in advance to cancel his bookings. One Jewish website recalls a US tour where Irving was forced to stay in cheap motels.

The Community Security Trust, a London-based Jewish organisation, was also sceptical.

''Today Irving appears to have said that there were gas chambers but this has always been blindingly obvious,'' a spokesman said.

''It should only create news if he continues to say this upon leaving prison and seeks to challenge the opinions of those who use the perverted practice of Holocaust denial in order to goad and hate Jews.''