BBC journalist Andrew Gilligan has denied he "misquoted or misrepresented" Dr David Kelly in a report claiming Downing Street "sexed up" an Iraq weapons dossier.
David Kelly facing MPs last week
BBC director of news Richard Sambrook earlier revealed Dr Kelly was the report's principal source after speaking to the family of the Iraq weapons expert, who was found dead on Friday.
Last week Dr Kelly told MPs he had spoken to Mr Gilligan but did not believe he was the main source for the report on BBC Radio 4's Today programme.
The senior Ministry of Defence adviser said: "From the conversation I had I don't see how he could make the authoritative statement he was making from the comments I made."
On Sunday, Mr Gilligan said Dr Kelly had "expressed very similar concerns about Downing Street interpretation of intelligence in the dossier and the unreliability of the 45-minute point" in both a meeting with him and in a separate interview for BBC Two's Newsnight programme.
"These reports have never been questioned by Downing Street," Mr Gilligan added.
The journalist's Today report said "a senior official" had told him the claim that Saddam Hussein's "military planning allows for some of the weapons of mass destruction to be ready within 45 minutes of an order to use them" had been "included in the dossier against our wishes because it wasn't reliable".
Downing Street communications director Alastair Campbell criticised BBC director of news Richard Sambrook for allegedly saying Mr Gilligan's source was "in the intelligence services" during a subsequent interview on Today.
On Sunday, Mr Gilligan said: "Although Dr Kelly had close connections with the intelligence community none
of our reports ever described him as a member of the intelligence services, but as a senior official closely involved in the preparation of the dossier."
Mr Sambrook said the corporation believed it correctly interpreted and reported the information obtained from Dr Kelly during interviews.
He said the BBC had, until now, owed Dr Kelly a duty of confidentiality and was "profoundly sorry" that his involvement as the source for the reports had ended in tragedy.
Dr Kelly's body was discovered in woodland near his Oxfordshire home on Friday morning, with a knife and a packet of painkillers close by.
A post mortem examination revealed he had bled to death from a slit wrist.
'Respect and restraint'
Prime Minister Tony Blair, speaking as he left Korea for China, said of Mr Sambrook's statement: "I am pleased that the BBC has made this announcement. Whatever the differences, no one wanted this tragedy to happen.
"I know that everyone, including the BBC, have been shocked by it. The independent Hutton Inquiry has been set up, it will establish the facts.
"In the meantime our attitude should be one of respect and restraint, no recrimination, with the Kelly family uppermost in our minds at this time."
The government has set up an independent judicial inquiry, led by Lord Hutton, into the circumstances surrounding Dr Kelly's death. Both Mr Blair and the BBC have said they will cooperate fully.
Mr Sambrook's statement prompted Dr Kelly's local MP, Tory Robert Jackson, to call for the resignation of the BBC chairman Gavyn Davies.
Ex-Labour minister Glenda Jackson has called for Tony Blair to quit, saying the blame for Dr Kelly's death lay with Downing Street, which, she said, had used a battle with the BBC to divert attention from the failure to find weapons of mass destruction in Iraq.
Tory leader Iain Duncan Smith has called for Parliament to be recalled and for a broadening of the inquiry to investigate the government's handling of intelligence on Iraq.
The prime minister said he would accept responsibility for all the actions of government ministers and officials, but ruled out recalling Parliament.