The inquiry into alleged child abuse by British TV presenter Jimmy Savile is now a formal criminal investigation involving other living people, Scotland Yard said today.
Operation Yewtree has moved from an assessment to a criminal investigation after detectives established there are lines of inquiry involving "living people that require formal investigation".
Scotland Yard said two weeks of gathering information has involved assessing more than 400 lines of inquiry and has identified more than 200 potential victims.
The force said: "As we have said from the outset, our work was never going to take us into a police investigation into Jimmy Savile.
"What we have established in the last two weeks is that there are lines of inquiry involving living people that require formal investigation."
Operation Yewtree, originally an "assessment" into claims against Savile, was launched after allegations flooded out in the wake of an ITV documentary screened earlier this month.
Today the National Society for the Prevention of Cruelty to Children in Britain said it is possible the former Top of the Pops presenter was "one of the most prolific sex offenders" the charity has ever come across.
Claims have also emerged about fellow entertainers Freddie Starr, who has staunchly refuted the allegations, as well as Gary Glitter - real name Paul Gadd.
As well as police investigations, inquiries are taking place into his involvement with Stoke Mandeville Hospital, Broadmoor and Leeds General Infirmary.
Dame Janet Smith, who headed the Shipman Inquiry, has been appointed to head an inquiry into Savile's time at the BBC and today Scotland Yard said they recognised "her need to progress this important work".
"We are now in a position to advise the BBC that they can ask the chair of the BBC Executive Board Dame Fiona Reynolds to begin her review to run parallel to our investigation.
"We will develop a protocol to ensure any future potential criminal action is not jeopardised."
It has also emerged that the BBC is aiming to rush a special edition of Panorama into its schedules looking into issues surrounding Jimmy Savile's years of abuse, which could be run on Monday.
Meanwhile, Gloucestershire police have been contacted by two women who claim they were sexually assaulted by Sir Jimmy Savile, the force said.
One assault is alleged to have taken place in the county, while the other was reported on Wednesday by a local resident who said she was assaulted elsewhere.
The force said the information had been passed to the Metropolitan Police, which is leading the investigation into alleged sexual abuse by the late TV presenter.