The BBC's governing body has asked former news executive Nick Pollard for an explanation about a recording which has been published online in which he discusses his failure to include some evidence in his report into the Savile scandal.
In the phone recording he talks about why he did not include a claim by the BBC's former director of news Helen Boaden that she had informed then-director-general Mark Thompson that a proposed Newsnight report was looking into sex abuse allegations against late DJ Jimmy Savile.
Mr Pollard led a review into the sequence of events surrounding Newsnight's shelved report into Savile's activities which eventually led to a huge crisis at the corporation and the departure of a later director-general, George Entwistle, after only 54 days in the post.
The edited recording, which lasts more than five minutes, was posted on the Guido Fawkes political blog, includes former Sky News chief Mr Pollard explaining that he did not include Ms Boaden's claim in the report because he did not recognise its significance at the time.
The review into the shelved Newsnight report into Jimmy Savile's abuse is to take about a month longer than expected.
The need to conduct further interviews, examine documents and prepare the report will mean it is not expected to be delivered until mid-December.
Former Sky News boss Nick Pollard, who is chairing the review, said it was making "good progress".