The inquiry into alleged child abuse by Jimmy Savile is now a formal criminal investigation involving other living people, Scotland Yard said today.
Savile was a huge supporter of Stoke Mandeville Hospital in Buckinghamshire, and there have been claims in recent weeks that he abused patients there.
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."