BBC reporter Andrew Gilligan has attacked members of the foreign affairs committee after being accused of changing his story on the government's intelligence dossier on Iraqi weapons of mass destruction.

Gilligan has become embroiled in the row since reporting that Number 10 communications director Alastair Campbell "sexed up" the dossier by inserting a claim that the alleged weapons could be launched within 45 minutes.

At an initial appearance before the committee, the journalist stood by his story. That prompted Campbell to attack the BBC's refusal to apologise for a story that was "a lie".

The government has also become embroiled in the row, with numerous Cabinet ministers calling on the corporation to retract the claim or name their source.

Members of the committee concluded that Campbell had not inserted the claim into the dossier.

And on Thursday afternoon in a closed session the MPs heard further evidence from Gilligan.

The exchanges later prompted a furious row between the BBC and the committee.

Donald Anderson, chairman of the committee, emerged from the session to accuse Gilligan of changing parts of his story.

"In the view of the committee this was an unsatisfactory session with a most unsatisfactory witness," he said.

"Mr Gilligan clearly changed his ground in the course of the evidence: in particular, in relation to serious allegations concerning Mr Campbell, director of communications at Number 10, and any responsibility of Mr Campbell for the insertion of the '45 minute point' in the dossier of September 24 2002.

"Potentially there is a grave danger of unfairness to Mr Campbell as a result."

But the journalist denied that he had altered his story claiming the committee was "quite determined to lynch me".

He stood by the assertion that Campbell inserted the 45-minute weapons claim.

"Nothing I have said to the committee conflicts with that," Gilligan added.

But following the discovery of a body believed to be that of Dr David Kelly, the man suspected of being Gilligan's source for his initial report, both the BBC and the committee will come under pressure to re-examine their role in the affair.

Last Tuesday Dr Kelly had given evidence to the foreign affairs committee after being named as the potential source by the Ministry of Defence.

He had been closely questioned by MPs, coming under pressure to explain his role in the affair.

Andrew MacKinlay accused Dr Kelly of being "chaff" who had been "set up" by ministers to divert attention from more serious issues.