BBC director-general George Entwistle was told that ITV was planning to run a documentary alleging that Jimmy Savile abused children a month before the programme aired, leaving questions over his answers to MPs on what he knew in advance of the scandal and how he reacted to it.
ITV wrote to BBC bosses in September this year, ahead of its bombshell Exposure programme the following month, which detailed claims that Savile had abused children.
The letter, received by the BBC on 7 September and forwarded to Mr Entwistle and others – known to include the director of news, Helen Boaden – detailed allegations that Savile had abused girls, and offered the BBC a right of reply.
The head of communications at the BBC is understood to have replied to the letter saying it could find no allegations against Savile in its archives. However, Mr Entwistle will have to explain why he allowed claims made in a blog by Newsnight editor Peter Rippon to go unchallenged until the BBC corrected it nearly three weeks later. The ITV letter pre-dated Mr Rippon's blog by nearly a month.
In the blog of 2 October, Mr Rippon wrote that Newsnight had no evidence against the BBC, but on 22 October the BBC admitted that the post contained some "misleading" assertions.
It said: "The blog says that Newsnight had no evidence against the BBC. No allegation was made to the programme that BBC staff were aware of Mr Savile's alleged activities, but there were some allegations of abusive conduct on BBC premises."
And on 23 October, hours after the BBC made changes to the blog, Mr Entwistle told MPs at the Culture, Media and Sport Select Committee that he had initially stood by Mr Rippon's handling of the story – that Mr Rippon dropped the investigation for editorial reasons, namely on whether the police dropped the Savile charges because he was too old – something Newsnight journalists who worked on the investigation disputed.
But at the committee, Mr Entwistle said he asked Mr Rippon to "step aside because of my disappointment at the inaccuracies in the blog", and said he was "disappointed" because he relied on "the editor of a programme having a full grip and understanding of the investigation they were in charge of, and in this case it doesn't seem to have been happening". He further added he "absolutely would have expected the editor of a programme to have given a definitive and factually accurate account of what happened on that programme".
A BBC spokeswoman last night confirmed: "An email from ITV was sent to the BBC corporate press office and on 7 September was forwarded to a number of people, including George Entwistle.
"Once his office had received the letter from ITV, Entwistle instructed the relevant teams within the corporation to work on a response which he authorised and which was sent to ITV within the agreed timeframe." It is understood a return letter was sent to the BBC.
A very well-placed BBC source said of the revelation: "This does make me believe that there is something very strange going on. They [the BBC] knew about this for weeks but they still let the blog go out there."
The disclosure will come as an embarrassment to Mr Entwistle just as the Pollard review into why the Newsnight investigation was dropped begins to hear evidence tomorrow.
Those due to be interviewed imminently by Nick Pollard, the former head of Sky News, include the chairman of the BBC Trust, Lord Patten.