The BBC has said it is investigating nine allegations of “sexual harassment, assault or inappropriate conduct” among current staff and contributors.
The admission comes after director general George Entwistle was urged to "get a grip" on his organisation during a hostile grilling by MPs about the broadcaster's handling of claims of sexual abuse by former presenter Jimmy Savile over several decades.
Mr Entwistle originally said there were "between five and 10 serious allegations" but a subsequent BBC statement said the corporation was "currently aware of nine allegations of sexual harassment, assault or inappropriate conduct regarding current staff or contributors".
"Some of these cases have been passed to the police where appropriate, and we are reviewing others within our normal HR processes and procedures."
Earlier today, Mr Entwistle told the Commons Culture, Media And Sport select committee that Savile's alleged behaviour had been possible only because of a "broader cultural problem" at the BBC.
Opening the hearing, the director general defended the corporation's handling of the case - including setting up two independent investigations.
"I would accept that there have been times when we have taken longer to do things than in a perfect world I would have liked," he said.
"But I think if you looked at what we have achieved since the scale of the crisis became clear, I think you see we have done much of what we should have done and done it in the right order and with proper respect paid to the right authorities."
Mr Entwistle also faced criticism over the decision not to broadcast a Newsnight investigation, including interviews with Savile's victims, last year.
His appearance before the committee came the morning after the BBC's Panorama programme broadcast an investigation into Savile and into the decision to ditch the Newsnight film, at a time when he was head of TV.
Newsnight editor Peter Rippon stepped aside yesterday after the BBC said his explanation of why the show dropped its investigation into Savile was "inaccurate or incomplete".
Mr Entwistle said the scandal raised questions of trust and reputation in the BBC.
He told MPs: "There's no question that what Jimmy Savile did and the way the BBC behaved - the culture and practices of the BBC seemed to allow Jimmy Savile to do what he did - will raise questions of trust for us and reputation for us. There's no question about that.
"It is a gravely serious matter and one cannot look back at it with anything but horror that his activities went on as long as they did undetected.
"Of course, that is a matter of grave regret to me."
Mr Entwistle said the inquiry by Nick Pollard, former head of Sky News, into why the Newsnight investigation into Savile was dropped is expected to report back "in weeks".
He admitted Mr Rippon's blog account was "a matter of regret and embarrassment".
Mr Entwistle told the committee he had ordered an internal audit of the operation of the BBC's child protection policies and would report its results to the BBC Trust in December.
He said: "So far as I have been able to tell so far, Mr Savile prosecuted his disgusting activities in a manner that was very successfully and skilfully concealed.
"Experts in paedophile behaviour have pointed out that this is often the case... People build long-range plans to put them in contact with their targets. These things are institutionally, it seems, very difficult to deal with."
The director-general told MPs he believed the Newsnight investigation into Savile should have continued and said there had been a "breakdown of communication" between Newsnight reporters and the editor and he did not feel "confident" that he could get an explanation over what happened from within the BBC.
Conservative MP Therese Coffey branded "chilling" an email sent by Mr Rippon last November that said "our sources so far are just the women" and questioned whether the culture had really changed at the BBC.
"That phrase, on the face of it, isn't in the least defensible, of course," he said. "I do believe the culture has changed since the Seventies and Eighties but I'm not convinced it has changed as much as it should have."
Mr Entwistle told the committee he had not spoken to any of those involved in preparing the Newsnight film.
He said he felt it was better to operate through the BBC "chain of command", so he could remain an impartial judge of any subsequent disciplinary case, and had left it to head of news Helen Boaden and deputy director of news Stephen Mitchell to deal directly with the programme.
Mr Entwistle said Ms Boaden had spoken to the Newsnight team only briefly during the investigation.
"I understand that Helen's only conversation with Peter in respect of the Newsnight investigation was to remind him that, just because Jimmy Savile was dead, it didn't mean that there could be any skimping in journalistic standards, and that the usual BBC standards would apply," said Mr Entwistle.
Mr Entwistle denied any personal failing, despite being pre-warned that the Newsnight investigation could have an impact on plans to broadcast a television tribute to Savile.
He gave the committee his account of a brief conversation with Ms Boaden in which she alerted him to the potential impact on the scheduled Boxing Day programme.
Pressed by Mr Whittingdale as to what he thought at the time the nature of the allegations against Mr Savile might be, he said: "I don't remember reflecting on it. This was a busy lunch.
"It wasn't that I didn't want to know. What was in my mind was this determination not to show an undue interest."
Conservative committee member Philip Davies said: "It appears that your determination not to show an undue interest applies to everything at the BBC, from today's performance.
"It's not just a lack of curiosity - although it certainly is that - from somebody who has been a journalist, but given that you are putting on these programmes, surely you must have wanted to ask whether or not you can stand something up on Newsnight, is it still appropriate for the BBC to be putting on tribute programmes to this person?"
Asked whether Mr Rippon might have been acting with too much risk-aversion when he decided to pull the Savile story, Mr Entwistle said: "It is important to recognise during a time like this that 95%-plus of what the BBC does is still going on.
"We have a very, very grave and serious issue here that has to be dealt with, but the imperative for the organisation to be creatively and journalistically adventurous is incredibly strong.
"It is something I intend to devote time and focus to, trying to eliminate creative risk-aversion and journalistic risk-aversion if I find it and ensuring we are absolutely as bold as we should be."