David Cameron is facing Labour demands to set up an independent inquiry into the Jimmy Savile sex abuse scandal.
Labour leader Ed Miliband insisted that a broad inquiry into Savile's activities at the BBC, Stoke Mandeville hospital and Broadmoor was essential to "do right by the victims".
Culture Secretary Maria Miller has dismissed calls for an independent inquiry, saying she was "confident" BBC chiefs were taking the claims "very seriously".
But Mr Miliband said the BBC's internal investigations were not enough.
Speaking to ITV1's The Agenda, he said: "These are horrific allegations. In order to do right by the victims I don't think the BBC can lead their own inquiry.
"We need a broad look at all the public institutions involved - the BBC, parts of the NHS and Broadmoor. This has got to be independent."
BBC director-general George Entwistle is expected to be questioned by MPs on the Culture, Media and Sport Select Committee next week.
Mr Entwistle has announced that two inquiries would be launched into the abuse claims. One will look into whether there were any failings over the handling of the abandoned Newsnight piece. A second independent inquiry will look into the "culture and practices of the BBC during the years Jimmy Savile worked here", Mr Entwistle said.
Police believe the DJ and television presenter's alleged catalogue of sex abuse could have spanned six decades and included around 60 victims.