The BBC's governing body has asked former news executive Nick Pollard for an explanation about a recording which has been published on the Order-Order blog 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.
The report was due to air in December 2011 and would have blown open the Savile sex abuse scandal. Instead it was shelved and the BBC chose to air a Christmas tribute to Savile.
The Savile sex abuse claims were eventually aired by ITV in October last year.
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, includes Pollard explaining that he did not include Boaden's claim in the report because he did not recognise its significance at the time.
Thompson, who is now chief executive of the New York Times, has said he was not aware of sex abuse allegations and has denied he was informed about them.
The exclusion of the evidence was reported earlier this year.
In March, Pollard is said to have written to Conservative MP Rob Wilson, who has taken an interest in the saga and was in possession of the tape, to say the conflicting evidence of Boaden and Thompson "does not change the conclusions I reached in my report in relation to Mr Thomson and his involvement".
The BBC Trust said it had written to Pollard to ask him to give an account of his comments in the recording.
The Order-Order website suggested today that BBC Trust chairman Lord Patten had issued a legal warning to Wilson if the tape is published. But the Trust said today that he had merely reminded him of the legal position of doing so.
A BBC Trust spokeswoman said: "There was no legal threat – the letter merely suggested Mr Wilson might want to satisfy himself the recording was not defamatory, should he decide to release it.
"Lord Patten is quite clear that it is entirely for Mr Wilson to decide what he does with the recording, which we have passed to Nick Pollard so that he has the opportunity to give us his account of the conversation in question."