The respected British investigative journalist, Tom Mangold, yesterday called on the BBC to say whether it believed allegations made over the Iraq dossier were true.
Mr Mangold, a friend of Dr David Kelly, the dead weapons expert now confirmed as the source of the BBC's claims, said he believed Dr Kelly's information provided 60 per cent of the story.
He also accused the BBC of acting in an "odd" manner and questioned the involvement of the corporation's senior managers. Mr Mangold said it was now up to the broadcaster to substantiate the rest of the story, in particular allegations that the dossier was "sexed-up".
He told Sky News: "Does the BBC believe these allegations to be true? Does the BBC still believe these allegations were true? Where is the supporting evidence? It did not come from Kelly, where did it come from?"
Mr Mangold speculated that Andrew Gilligan, the journalist behind the story, may have had further sources.
He said: "We don't know and we may never know. We do have the right to know whether these allegations are true. The BBC are yet to confirm whether it believes these very serious allegations are true... I don't think the other sources should be revealed. That would be the end of investigative journalism."
He continued: "When Alastair Campbell, whom I don't know or don't think I want to know, bangs the table saying 'it was not me, I did not put that stuff in the JIC [Joint Intelligence Committee] report', it seems that he is probably speaking the truth."
Of the BBC allegations, he said: "Are they true, are they just credible or are they just false? All the evidence points to the fact that they may be false."
The BBC itself confirmed yesterday that Dr Kelly was the source for Mr Gilligan's allegations that intelligence on Iraq was "sexed up".
A statement issued yesterday by the BBC's head of news, Richard Sambrook, said: "The BBC deeply regrets the death of Dr David Kelly. We had the greatest respect for his achievements in Iraq and elsewhere over many years and wish once again to express our condolences to his family. There has been much speculation about whether Dr Kelly was the source for the Today programme report by Andrew Gilligan on May 29th. Having now informed Dr Kelly's family, we can confirm that Dr Kelly was the principal source for both Andrew Gilligan's report and for Susan Watts's reports on Newsnight [the BBC2 late-night news programme] on June 2nd and 4th."
The statement continued: "The BBC believes we accurately interpreted and reported the factual information obtained by us during interviews with Dr Kelly.
"Over the past few weeks we have been at pains to protect Dr Kelly being identified as the source of these reports. We clearly owed him a duty of confidentiality. Following his death, we now believe, in order to end the continuing speculation, it is important to release this information as swiftly as possible. We did not release it until this morning at the request of Dr Kelly's family.
"The BBC will fully co-operate with the Government's inquiry. We will make a full and frank submission to Lord Hutton [the Law Lord who will conduct the inquiry] and will provide full details of all the contacts between Dr Kelly and the two BBC journalists including contemporaneous notes and other materials made by both journalists, independently.
"We continue to believe we were right to place Dr Kelly's views in the public domain. However, the BBC is profoundly sorry that his involvement as our source has ended so tragically." - (Press Association)