The BBC is facing a mounting crisis over its handling of a Newsnight investigation into the Jimmy Savile sex abuse scandal.
Tonight's Panorama will claim the corporation pulled the segment after coming under pressure from senior managers.
The show, which goes out at 10.35pm on BBC One, also investigates why BBC chiefs gave different explanations about the nature of the documentary and why it was dropped.
In the aftermath, director general George Entwistle wrote to all staff saying the Newsnight investigation was into "Surrey Police's inquiry into Jimmy Savile towards the end of 2011".
But producer Meirion Jones immediately emailed Mr Entwistle countering that, writing: "George - one note - the investigation was into whether Jimmy Savile was a paedophile - I know because it was my investigation.
"We didn't know that Surrey police had investigated Jimmy Savile - no-one did - that was what we found when we investigated and interviewed his victims."
Tonight's hour-long documentary lifts the lid on the extent to which the higher echelons of the corporation were aware of the claims against the late DJ. Panorama includes contributions from BBC foreign editor John Simpson, who describes the scandal as "the worst crisis" in nearly 50 years at the BBC.
Newsnight editor Peter Rippon maintains the piece - which was due to run last December - was pulled for editorial reasons, and not because the potentially damaging revelations coincided with a planned tribute to the star. The BBC denied reports that Mr Rippon has resigned over the scandal.
The horror stories about Savile fully emerged only after ITV broadcast a documentary at the start of this month - sparking mayhem at the BBC over losing its scoop and leading to the allegations of a cover-up.
A Panorama statement said: "Peter Rippon has always maintained the story was pulled for 'editorial reasons' and not because of a potentially embarrassing clash with planned BBC tributes to Savile over Christmas.Panorama has found no evidence to contradict that view."