The inquiry into alleged child abuse by Jimmy Savile is now a formal criminal investigation involving people stiil living, Scotland Yard says.
Detectives have established there are lines of inquiry involving "living people that require formal investigation".
Scotland Yard said in the past two weeks officers have checked more than 400 lines of inquiry and have identified more than 200 potential victims.
A spokesman 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 was originally an "assessment" into claims against Savile, launched after a flood of allegations in the wake of an ITV documentary screened earlier this month.
Today the NSPCC 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.
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.
http://news.sky.com/story/9998...riminal-investigaton