Reporter Mr Andrew Gilligan has become the high-profile figure to resign from the BBC in the wake of the Hutton report.
In a statement tonight, Mr Gilligan said the British state broadcaster had been the victim of a "grave injustice".
The BBC said: "We can confirm that Andrew Gilligan has resigned. We recognise that this has been a very difficult time for him."
A radio report by Mr Gilligan that the British government "sexed up" intelligence on Iraqi weapons sparked the controversy which lead to the Hutton report into the death of Dr David Kelly.
Dr Kelly, a source for Mr Gilligan's story, killed himself after his name was made public.
Mr Gilligan conceded tonight that some of his story on the intelligence dossier about Iraq weapons of mass destruction before the war, was wrong, adding: "I again apologise for it. My departure is at my own initiative. But the BBC collectively has been the victim of a grave injustice."
He said he had not been forced to resign but was quitting to protect the institution he "loved".
In the lengthy statement, Mr Gilligan said: "I love the BBC and I am resigning because I want to protect it. I accept my part in the crisis which has befallen the organisation. But a greater part has been played by the unbalanced judgments of Lord Hutton."
He insisted the British government had "sexed up" its dossier - despite Lord Hutton's finding yesterday that it had not.
And he paid tribute to ex-director general Mr Greg Dyke who he described as "the finest" director general for a generation who should not have quit.
His resignation follows the top-level departures of Mr Dyke and BBC chairman Mr Gavyn Davies.
Agencies