The BBC says 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, 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 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 after the BBC said his explanation of why the show dropped its investigation into Savile was "inaccurate or incomplete".