Newsnight's Peter Rippon is to stand aside while the BBC reviews its response to the Jimmy Savile sex scandal, it was announced on Monday.
Rippon has become the first casualty of what John Simpson called "the worst crisis that I can remember in my nearly 50 years at the BBC."
The BBC's announcement comes ahead of a Panorama documentary to be aired tonight which will claim a Newsnight investigation into the Savile sex abuse scandal was pulled after pressure from senior managers.
A clarification from the corporation now said it was incorrect that Newsnight had no evidence about allegations against Savile by staff from the Duncroft approved school.
It adds that contrary to Rippon's blog "there were some allegations of abusive conduct on BBC premises."
It adds: "The blog says that all the women spoken to by the programme had contacted the police independently already and that Newsnight had no new evidence against any other person that would have helped the police. It appears that in some cases women had not spoken to the police and that the police were not aware of all the allegations."
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David Cameron has said it is "concerning" that the BBC effectively changed its story about why it dropped the Newsnight report.
"The nation is appalled, we are all appalled by the allegations of what Jimmy Savile did and they seem to get worse by the day," he said during questions and answers following a speech in London.
"The developments today are concerning because the BBC has effectively changed its story about why it dropped the Newsnight programme about Jimmy Savile.
The BBC said in a statement: "The BBC regrets these errors and will work with the Pollard Review to assemble all relevant evidence to enable the review to determine the full facts.
"In addition, the BBC has announced that Peter Rippon is stepping aside with immediate effect from his post while the review by Nick Pollard, the former head of Sky News, into the management of Newsnight's investigation, is carried out."
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."
The BBC Trust, the corporation's governing body, said it was "deeply concerning that there have been inaccuracies in the BBC's own description of what happened in relation to the Newsnight investigation".
In the aftermath of the cancelled investigation, BBC Director-General George Entwistle wrote to all staff saying that Newsnight was looking 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, which goes out on BBC1 at 10.35pm, will hear from Mr Jones and reporter Liz MacKean, who both claim they interviewed at least four alleged victims of Savile - and confirmed with Surrey Police that they had investigated sex abuse complaints against the Jim'll Fix It star in 2007.
They say that, when they told bosses the Crown Prosecution Service did not charge Savile because of insufficient evidence, they were told to end the investigation - and the show was withdrawn.
The horror stories about Savile 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.
Ms MacKean said: "Ever since the decision was taken to shelve our story, I've not been happy with public statements made by the BBC.
"I think they're very misleading about the nature of the investigation we were doing."
The Newsnight journalists filmed Karin Ward, a key witness, in mid-November saying that Savile abused her during her time at Duncroft.
She claims she saw pop star Gary Glitter having sex with another under-age girl from Duncroft on BBC premises.
Ms Ward has agreed Panorama can broadcast clips from the interview for the first time in the programme Jimmy Savile: What The BBC Knew.
Newsnight quoted three other unnamed former Duncroft pupils who said they were also sexually abused by Savile. The script included a report of sexual abuse of a teenager at Stoke Mandeville Hospital.
Ms MacKean said Mr Rippon suddenly went cold on the story: "All I can say is that it was an abrupt change in tone from, you know, one day 'Excellent, let's prepare to get this thing on air' to 'Hold on'."
She says she was left with the clear impression that her editor was feeling under pressure, writing to a friend: "PR (Peter Rippon) says if the bosses aren't happy... (he) can't go to the wall on this one."
The programme also reveals that BBC director of news Helen Boaden told Mr Entwistle - at that time director of vision - about the Newsnight investigation and its possible impact on planned tributes to Savile during an awards lunch on December 2.
She told him that, if the Newsnight investigation went ahead, he might have to change the Christmas schedules.
Mr Jones emailed Mr Rippon five days later to warn him about what would happen if the investigation was dropped.
"I was sure the story would come out one way or another and that, if it did, the BBC would be accused of a cover-up," Mr Jones tells Panorama.
"In fact, I wrote an email to Peter saying 'the story is strong enough' and the danger of not running it is 'substantial damage to BBC reputation'."
Two days later, Mr Rippon decided to kill the investigation, Panorama reports.
The latest development will put even more focus on Mr Entwistle's appearance tomorrow before the Culture, Media and Sport Select Committee.
Its chairman, MP John Whittingdale, said earlier today that the most important question the BBC faces is why the investigation was dropped.
He told Sky News: "Whilst Panorama say there is no evidence the editor was leant on from outside, the explanations originally given look very thin today."
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Posted: 22/10/2012 11:33 BST Updated: 22/10/2012 14:06 BST