Former BBC director general Mark Thompson has accused BBC Trust chairman Lord Patten of misleading Parliament over pay-offs to departing bosses at the corporation.
He claims Lord Patten and BBC Trustee Anthony Fry told "specific untruths and inaccuracies" in evidence to MPs investigating the controversial golden goodbye deals.
Mr Thompson, who is now Chief Executive of The New York Times, is due to appear before the Commons Public Accounts Committee (PAC) on Monday.
Speaking to Sky News, he said would not be adding to his written submission before the hearing, saying "the first questions I want to answer are those from the MPs".
In his lengthy written submission ahead of the hearing he insisted that Lord Patten had been "fully briefed" about the details of severance packages to former deputy director general Mark Byford and former marketing chief Sharon Baylay.
Lord Patten, however, told Sky News he found the focus on Mr Byford "curious" as it happened before he became Trust chairman.
Mr Thompson's evidence, published on the PAC website , said: "The picture painted for the PAC by the BBC Trust witnesses on 10 July 2013 was - in addition to specific untruths and inaccuracies - fundamentally misleading about the extent of Trust knowledge and involvement.
"The insinuation that they were kept in the dark by me or anyone else is false and is not supported by the evidence."
In evidence in July Mr Fry told the PAC that members of the Trust were not always included in decision-making.
He also said there was "some disconnect" in what Mr Thompson had written in a letter to the Trust about Mr Byford's pay-off, in which he had apparently declared it was within contractual arrangements, when the National Audit Office (NAO) had found it was not.
Mr Byford departed with a total payout of £949,000 and Ms Baylay's settlement was worth £394,638.
Mr Thompson said in his evidence that Lord Patten was told "in writing as well as orally", about the settlements soon after his arrival as chairman in 2011.
He concludes that the evidence given to the NAO and PAC was "inadequate, and in some important instances, very misleading testimony".
A BBC Trust spokesman said: "This is a bizarre document. We reject the suggestion that Lord Patten and Anthony Fry misled the PAC.
"We completely disagree with Mark Thompson's analysis, much of which is unsubstantiated, in particular the suggestion that Lord Patten was given a full and formal briefing on the exact terms of Mark Byford's departure, which in any event took place before the current chairman's arrival at the Trust."
Asked about Mr Thompson's challenge to Lord Patten, the Prime Minister's spokesman said: "It's very understandable that Parliament will want to scrutinise this area. That's what it's doing. We should let that process go forward."
In another development, departing HR boss Lucy Adams admitted making a mistake in her evidence to the committee.
Ms Adams, who said last month she was quitting the BBC, initially told MPs she had not seen a note detailing plans for pay-offs to Mr Byford and Ms Baylay - but now admits she helped write it.
"At the time, I was not clear which document the chair was referring to" but in written evidence she said: "I can confirm that I was involved in drafting that memo".
Ms Adams is due before the committee on Monday alongside Lord Patten, his predecessor Sir Michael Lyons, the former chairman of the BBC Executive Board Remuneration Committee Marcus Agius, Mr Thompson and Mr Fry.