Police are looking at 120 lines of inquiry and possibly as many as 25 victims relating to the Jimmy Savile sex abuse claims.
Scotland Yard has formally recorded eight criminal allegations against the star, including two of rape and six of indecent assault.
Commander Peter Spindler, head of Specialist Crime Investigations, said the allegations span four decades and information so far suggests abuse was on a "national scale". He said there are currently 120 lines of inquiry, although some could be duplicates.
Mr Spindler told reporters: "Information is coming in as we speak probably. The reality is this really has captured the public's mind. We are getting calls from victims, from witnesses and third parties who believe they know something about it.
"We have formally recorded eight criminal allegations against Savile. Two of those are rape, six of indecent assault. These are primarily against girls in their mid-teens, so between 13 and 16, and it spans four decades of abuse."
He said the first dated back to about 1959 but most seemed to be in the 70s and 80s. Scotland Yard has been in contact with ITV and the BBC to gather information, and they are contacting alleged victims they have been talking to to see if they will co-operate, he said.
Mr Spindler said they are working to identify anyone who could be subject to criminal investigation. The BBC is not being investigated, he said.
Asked if allegations related to any institutions other than those mentioned in previous claims - the BBC, the Jersey children's home, or the school in Staines - he said he had contacted Stoke Mandeville Hospital, and Leeds Royal Infirmary. "The pattern of his offending behaviour does appear to be on a national scale," he said.
Mr Spindler said police will produce a joint report with the NSPCC to look to see what lessons can be learned and what conclusions can be drawn, which can be shared with other agencies.
Calling it an "assessment", rather than an investigation, he said it is being carried out by Scotland Yard and being led by its Serious Case Team, which looks at complex and history cases.