A renegade British Catholic bishop who claimed that no Jews were killed in gas chambers during the Second World War was found guilty of Holocaust denial in a German court yesterday.

Bishop Richard Williamson, 70, a leading figure of an ultra-orthodox Catholic sect, the Society of St Pius X (SSPX), made the comments during an interview on Swedish television in 2008. The interview was conducted at a seminary in Germany, where denying the Holocaust is a criminal offence.

The court, in the Bavarian city of Regensburg, officially convicted the bishop of Holocaust denial and fined him £10,000 after he refused to attend a public trial.

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His lawyer, Matthias Lossman, told the court that Bishop Williamson's religious order had barred him from travelling from London where he is currently living. His legal team asked for an acquittal, arguing that while the cleric had "trivialised" the Holocaust he had specifically asked the Swedish television team not to broadcast their documentary in Germany.

The resulting programme, an investigation into the links between SSPX and far-right groups in Sweden, was not shown in Germany but was available on the internet and was viewed around the world.

Speaking on the programme from the seminary in Zaitzkoven, the elderly bishop, who describes himself as a "dinosaur" in his own blog, stated: "The historical evidence is hugely against six million Jews having been deliberately gassed in gas chambers as a deliberate policy of Adolf Hitler."

Instead, he claimed that between 200,000 and 300,000 had died in concentration camps "but not one of them by gassing in a gas chamber". The vast majority of historians put the Jewish death toll during the Holocaust at six million. His remarks ended up plunging the Vatican into a disastrous confrontation with the world's Jewish community, because Pope Benedict XVI had recently lifted an excommunication order on the controversial society.

The timing of the de-excommunication and the Vatican's initial silence on Bishop Williamson's remarks seriously undermined ecumenical relations between the Catholic Church and other world faiths, which had already been strained by a series of public gaffes from Pope Benedict. Eventually, the Vatican called on Bishop Williamson to apologise, but critics said the Pope's condemnation did not go far enough. The Society of St Pius X is regarded as a bastion of ultra-conservative Catholic theology. It broke away from Rome in protest at reforms brought in during the 1960s following the Second Vatican Council. Pope John Paul II eventually ordered the excommunication of the society's French founder, Arch- bishop Marcel Lefebvre and his five bishops after they refused to stop ordaining priests.

However, much of SSPX's theology appeals to Pope Benedict, who is much more conservative than his predecessor. He has always favoured a rapprochement with the traditionalist sect but the timing of Bishop Williamson's remarks made such a union politically explosive.

Since the controversial interview was broadcast, Bishop Williamson has been living a quiet existence at SSPX's UK headquarters in London, after he was thrown out of a seminary in Argentina where he had spent most of the past decade.

He has refused to give media interviews since his return. The Independent left messages with the society's London-based Great Britain Distruct Superior Father Paul Morgan yesterday asking him to explain why the order barred Bishop Williamson from travelling to Germany but the calls were not returned.

The £10,000 fine is £2,000 less than prosecutors had asked for. The court initially ordered Bishop Williamson to pay £12,000 but he refused, prompting the public trial. He now has one week in which to submit an appeal.