Policing investigators said yesterday that Jimmy Savile's 60-year reign of child abuse could have been stopped as early as 1964.
HM Inspectorate of Constabulary condemned forces around Britain and Northern Ireland for failing to stop the disgraced presenter.
HMIC also warned there was a "distinct possibility" that officers could fail to prevent a similar scandal from happening again.
Five allegations and two pieces of intelligence were recorded against Savile during his lifetime, HMIC found - and 450 individuals have come forward with abuse claims since the Met launched Operation Yewtree last October.
The earliest record uncovered naming Savile in connection with a sexual abuse investigation was dated 1964 - but officers failed to act on the intelligence.
The Met Police and NSPCC have found that Savile's offending spanned from 1955 to 2009.
Inspector Drusilla Sharpling said: "The findings in this report are of deep concern, and clearly there were mistakes in how the police handled the allegations made against Savile during his lifetime.
"However, an equally profound problem is that victims felt unable to come forward and report crimes of sexual abuse.
"It is imperative that all those charged with protecting these victims do more to encourage reporting, taking the right action to bring perpetrators to justice."
She said that while HMIC welcomed recently announced measures by the director of public prosecutions and Association of Chief Police Officers more needs to be done.
"It is neither enough nor correct to say 'This couldn't happen now'," she said.