Director of Public Prosecutions Keir Starmer is to review legal papers relating to abuse allegations against Jimmy Savile, David Cameron said.
The Prime Minister said it was essential that lessons were learned from the scandal of Savile's decades of sexual abuse.
He told MPs at Prime Minister's Questions: "The Director of Public Prosecutions has confirmed that his principal legal adviser will again review the papers from the time when a case was put to the CPS (Crown Prosecution Service) for prosecution.
"The Director of Public Prosecutions specifically is going to consider what more can be done to alert relevant authorities where there are concerns that a prosecution is not taken forward. The Government will do everything it can do, other institutions must do what they can do, to make sure that we learn the lesson of this and it can never happen again."
Children's charity the NSPCC said it has received 161 calls relating to Savile, which have been passed to police, and another 105 not related to the performer. These came from adults who wanted to discuss being abused as children following media coverage of the case, and 24 of those allegations have also been referred to the police, the charity said.
Mr Cameron: "The allegations and what seems to have happened are completely appalling and, I think, are shocking the entire country. These allegations do leave many institutions - perhaps particularly the BBC - with serious questions to answer - I think above all the question, 'How did he get away with this for so long?' The most important thing is that the police investigation is properly resourced and is allowed to continue. I don't rule out further steps but we do now have independent investigations by the BBC, independent investigations into the NHS."
Mr Cameron said he believed the two inquiries into the BBC over the Savile scandal were "independent".He told MPs: "The inquiry into the Newsnight programme is being carried out by the (former) head of Sky News Nick Pollard and the second, and more important in many ways, review into the culture and practices of the BBC going back many years is being led by a former appeal court judge, Dame Janet Smith. It's very important that the BBC makes clear these inquiries can go where the evidence leads, they'll have access to all the paperwork and they will be able to be truly independent and get to the truth on behalf of all the victims of Jimmy Savile."
Mr Starmer said evidence submitted to Surrey Police in 2009 was considered by prosecutors, but because the alleged victims would not support police action it was decided not to proceed. As the number of allegations against Savile recently snowballed, Mr Starmer asked the chief crown prosecutor for the South East, Roger Coe-Salazar, to look at the files again. He concluded that the correct decision was taken, although the files will again be reviewed "out of an abundance of caution".
Mr Starmer said: "Whilst it is sometimes possible to prosecute cases where the victim does not support a prosecution, there are obvious problems in proceeding with a case where the victim does not support a police investigation, where there is no forensic evidence and only very limited, or even in some instances no, witness evidence, particularly in relation to allegations which date back a number of years.
"Out of an abundance of caution I have asked for the papers in the four cases to be provided to my principal legal adviser, Alison Levitt QC, forthwith so that she can consider the decisions made and advise me accordingly. This is not a straightforward issue but I have said to the Attorney General that I would like to discuss with him whether the CPS should adopt a policy of referring cases to other relevant agencies, such as social services, where an allegation is made but cannot be proceeded with for evidential reasons."