Newsnight presenter Jeremy Paxman went too far when he talked about religious hogwash and stupid people who believe in the Old Testament, the BBC Trust has ruled.

Paxman made the comments in an interview with Professor Richard Dawkins, the outspoken author of The God Delusion, prompting one viewer to complain that the presenter of BBC2's Newsnight was biased and offensive.

The trust's editorial standards committee rejected the accusation of bias, but said Paxman might have unintentionally caused offence with the comments which had no clear editorial purpose.

Originally, BBC management rejected the complaint in its entirity, denying that Paxman had shown any anti-Christian bias and saying the presenter had played devil's advocate to Dawkins, who was on the programme to talk about his new book, The Magic of Reality: How We Know What's Really True, on 13 September 2011.

However, the complaint then went to the BBC Trust editorial standards committee, which ruled that Paxman had a well-known interviewing style and viewers would have expected a lively discussion between the pair on the programme.

The committee said there was a clear editorial purpose for Paxman's use of the word 'myth' in the item, and noted that the BBC said that when the Newsnight host used the word 'hogwash' he was clearly referring to myths rather than all religion.

"However, the committee recognised that some Newsnight viewers were unlikely to have expected Jeremy Paxman's typically robust and confrontational interviewing style to extend to the use of the terms 'religious hogwash' when introducing the story of Genesis, and 'stupid people' when talking about those with a literal belief in the Old Testament in the context of the item about religious myths," the committee said in its ruling, published on Tuesday.

"Although the committee did not agree with the complainant that Mr Paxman's use of the terms 'religious hogwash' and 'stupid people' were intended to cause deliberate offence, particularly to those with religious views and beliefs, it nevertheless agreed that they were offensive to some of the audience and that there was no clear editorial purpose for their use in the context of this Newsnight item, taking account of generally accepted standards.

"The committee therefore concluded that the item breached the editorial guidelines on harm and offence. It added that it regretted the offence caused to some viewers by the use of the terms 'religious hogwash' and 'stupid people' on this occasion."

A BBC News spokeswoman said: "Newsnight notes the trust's finding that viewers may have found some of the comments offensive, but also welcomes the finding that the piece achieved due impartiality."

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