The Newsnight editor, Peter Rippon, is to step aside, as the BBC was forced to admit that his programme was aware of allegations that Jimmy Savile had abused teenagers on the corporation's premises and had unearthed information not previously known to the police.

The BBC said that Rippon's initial explanation as to why he killed off a Newsnight investigation into Savile in December of last year was "inaccurate or incomplete in some respects". The corporation has made three corrections to a blogpost written by Rippon, which was published on 2 October, when the Savile abuse allegations first became public.

In one correction, the BBC said that Rippon was wrong to write "we found no evidence against the BBC". In fact, the Newsnight team had uncovered "some allegations of abusive conduct on BBC premises" – although there was "no allegation" that BBC staff were aware of Mr Savile's alleged activities.

The BBC also determined that Rippon was incorrect when he wrote: "We are confident that all the women we spoke to had contacted the police independently already. We also had no new evidence against any other person that would have helped the police."

Instead, the BBC statement continued, the truth was that "It appears that in some cases women had not spoken to the police and that the police were not aware of all the allegations." Newsnight's key evidence came from Karin Ward, who said she had been a victim of Savile and who had repeatedly told programme makers she had never gone to the police.

The third correction demanded is more minor. The BBC notes that Rippon had said there was no evidence that anybody from Duncroft approved school, where Savile appears to have perpetrated abuse in the 1970s, "could or should" have known about the allegations. In fact, the correction continues "some allegations were made (mostly in general terms) that some of the Duncroft staff knew or may have known about the abuse."

Lord Patten's BBC Trust also weighed in, saying it was "deeply concerning" that there had been "inaccuracies in the BBC's own description of what happened in relation to the Newsnight investigation". The trust said that it was right that BBC director general George Entwistle had corrected those inaccuracies – and had demanded and received confirmation that the impending Nick Pollard inquiry will also establish why Rippon's blog needed to be corrected.

It is understood that Rippon remains on full pay and has not, despite earlier suggestions, been suspended. He has been asked to co-operate with the Nick Pollard inquiry.

Rippon's move comes hours before a Panorama investigation into what happened at Newsnight in November and December of last year airs on BBC1. The one-hour programme focuses intensely on Rippon and his decision to halt his programme's investigation into Savile.

Emails seen by Panorama will show that Rippon was initially keen on airing the Newsnight investigation, which had gathered information on abuse by the Jim'll Fix It star from women who had lived at Duncroft in the 1970s.

But he suddenly changed his mind between 25 November and 30 November last year – demanding that reporters on the investigation prove that the Crown Prosecution Service chose not to charge Savile in 2007 because he was too old – a hurdle the Newsnight team thought was unachievable.

Newsnight reporter Liz MacKean believed that Rippon was feeling under pressure from his bosses, writing in an email to a friend on 30 November that: "PR [Peter Rippon] says if the bosses aren't happy … [he] can't go to the wall on this one." But Rippon says that he had always dropped the film for "editorial reasons".

Had the Newsnight film run, the BBC2 programme would have been the first to reveal that Savile was linked to sexual abuse. Instead, earlier this month, an ITV documentary was first to expose Savile – whose teenage victims, the Met police said earlier this week, may number in excess of 200.

Rippon denies that he was placed under any pressure to drop the investigation and says that the decision was based on editorial considerations as he honestly judged them at the time.

He joined Newsnight in 2008 – and had previously worked at Radio 4 as the editor of PM and The World at One. But his reign at the programme so far has been underscored by long-term decline in viewing, with one programme being viewed by as few as 200,000 people.

David Cameron said on Monday it was "concerning" that the BBC effectively changed its story about why it dropped the Newsnight report on Savile.

The prime minister said the announcement that Rippon had stood aside and the BBC had sought to correct his original blog explanation for the decision to drop the Newsnight investigation last December raised "serious questions".

He told reporters following a speech in London on Monday: "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.

"So every organisation that was involved with him – whether the NHS or whether the BBC – needs to get to the bottom of what happened.

"The developments today are concerning because the BBC has effectively changed its story about why it dropped the Newsnight programme about Jimmy Savile.

"These are serious questions, they need to be answered. They need to be answered by these independent reviews that the BBC has established and I am sure that they will be."

Damian Collins, a Conservative MP on the Commons culture, media and sport select committee, said it would discuss on Tuesday whether to launch a broader investigation into Newsnight's Savile report.

Entwistle is due to appear before the committee on Tuesday morning to face questions about the BBC's handling of the Savile sex abuse scandal.

Collins told the Guardian: "I think that the committee will have to discuss it when we meet tomorrow.

"Now we know the BBC had new witness statements, why did they sit on them at the time? Why didn't they hand them to the police? It's a big question for me for George Entwistle tomorrow and it's a big gap in the internal investigations that they have launched.

"I want to hear what George Entwistle has to say about this tomorrow and the BBC has to conclude it's own investigation in December. It will be discussed when we meet privately before [Entwistle appears] tomorrow morning. It may be the best time [to launch a broader investigation] is in December because it's not far away. I'd like to see what is said by Entwistle first and see the Nick Pollard review in December."

Sir Christopher Bland, the former BBC chairman, told the BBC News channel the allegations were "very serious" but warned against jumping to conclusions about Rippon stepping aside.

"It is very early days and the atmosphere is so heady that it's foolish to jump to huge and overarching conclusion," Bland said.

"Until those investigations take place and we can see what they reveal then I think everybody needs to be careful about jumping to conclusions. All these are serious charges and I wouldn't disagree with John [Simpson]'s view that is it serious, but the worst for 50 years? Let's see what the investigations come up with."

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