BBC journalist Andrew Gilligan has admitted making mistakes in live broadcasts reporting claims the government had "sexed up" its dossier on Iraq's weapons of mass destruction.
Mr Gilligan stood by the story he based on a conversation with government weapons expert Dr David Kelly.
But under tough cross-examination at the Hutton inquiry into Dr Kelly's death, Mr Gilligan said he had made "slips of the tongue" in unscripted broadcasts.
He was followed into the witness box by BBC director of news Richard Sambrook, who said there were errors in the BBC's strongly-worded response to the government's complaints about the dossier story.
Mr Sambrook also said the dossier story should have been put to Downing Street before it was broadcast.
Dr Kelly's apparent suicide came after he was named as the suspected source for Mr Gilligan's report.
The BBC defence correspondent said he had agreed at his meeting with Dr Kelly that he would describe his source as "one of the senior officials in charge of drawing up the dossier".
Mr Gilligan also told his programme editors that Dr Kelly had played a prominent role in the dossier.
But the government's QC at the inquiry, Jonathan Sumption, said: "He never said any such thing to you did he?"
"Yes, he did," countered Mr Gilligan.
But he admitted a "slip of the tongue" when he talked of his "intelligence service source" when referring to Dr Kelly in a Radio Five Live broadcast.
Jeremy Gompertz, the QC acting for Dr Kelly's family, challenged Mr Gilligan's account of his conversation with the late scientist.
Mr Gompertz suggested it was Mr Gilligan, not Dr Kelly, who first mentioned the name of Downing Street media chief Alastair Campbell as they discussed who was responsible for transforming the dossier in the days before its publication.
That claim was rejected by Mr Gilligan, who also denied he had played a "name game" with Dr Kelly, something the scientist's friend Olivia Bosch had suggested.
Mr Gilligan also apologised for e-mailing an MP on the committee which was looking into his BBC story about the government's presentation of its case for war with Iraq.
It was "quite wrong" of him to have suggested Dr Kelly was the source for BBC Newsnight reports about Iraqi weapons, he said, especially as he was not sure at the time who the source was.
In his defence, Mr Gilligan said he had been under "enormous pressure" when he sent the e-mail.
He said Dr Kelly had not directly told him the government knew intelligence included in its dossier about Iraqi weapons of mass destruction was wrong or unreliable.
Gilligan was accused of trying to mislead MPs
But the scientist had said the claim that such weapons were ready for use in 45 minutes was "unreliable, that it was wrong, and that it was included against our wishes".
Mr Gilligan went on: "It was a logical conclusion to draw from this that those wishes had been made known, as we now indeed know to have been the case."
The mistaken impression he gave "was not intentional, it was the kind of slip of the tongue that does happen often during live broadcasts".
BBC chief's 'dilemma'
Mr Sambrook said the BBC had been under "considerable pressure" to respond to Number 10's complaints but should have considered at greater length the charges levelled against it.
In particular, he had been wrong to say the source for the story was somebody "senior and credible" in the intelligence services.
The next day, Mr Sambrook was told for the first time that the source was Dr Kelly and it became clear he was not a member of the intelligence services.
Asked why the statement, which was repeated on other BBC broadcasts, was not corrected, he said he had faced a "dilemma".
"Clearly it would be preferable to be absolutely accurate about it but
equally we had a dilemma as we didn't wish to do anything which might lead to
the identification of our source," the BBC executive told the inquiry.
On balance, he had decided he had a greater duty of confidentiality to Dr Kelly.
Mr Sambrook also said he had not told BBC governors that the source was not in fact a senior member of the intelligence services, but said they were not overly interested in the source's identity.
He said Mr Gilligan was "extremely good at finding out information, but there are sometimes questions of nuances and subtlety in how he presents it which are not all they should be".
Lord Hutton asked if it was appropriate for the BBC to rely entirely on Andrew Gilligan if serious complaints had been made about his story and his notes did not fully support that report.
Mr Sambrook said it was not possible to corroborate the story. But Mr Gilligan had been consistent when questioned and another BBC correspondent appeared to have had similar conversations.
The inquiry also heard again from MoD personnel director Richard Hatfield, who rejected suggestions that Dr Kelly's pension was at any risk as he was questioned about his BBC contacts.