At least seven alleged victims of Jimmy Savile made complaints of sexual abuse against him while he was still alive, it emerges.
Scotland Yard has admitted four police forces were aware in the 1980s of claims against the former TV presenter and DJ.
The first of the seven claims was made in the 1980s by a young girl, who said she had been subjected to an indecent assault at BBC TV Centre.
Subsequent claims were made between 2003 and 2008, all relating to alleged instances of sexual abuse during the 1970s.
Commander Peter Spindler said the Metropolitan Police were now dealing with around 300 potential victims, of whom all except two are women.
They have been separated into three categories: those allegedly abused by Savile, those allegedly abused by Savile and others and those allegedly abused by others on their own.
Mr Spindler claimed Savile was one of the most prolific sex offenders in recent history and that the inquiry into his alleged abuse would be a "watershed" investigation into sex crime.
He said an "arrest strategy" was being devised, but that police had yet to detain anyone under caution.
Child safety expert and former Met detective Jonathan Taylor told Sky News why Savile may have escaped police action during his lifetime.
"It's very different to have evidence to arrest somebody than the amount of evidence required for a prosecution and subsequent conviction," he said.
"If a victim isn't willing to go to court and actually stand up and say, 'This is what happened to me,' then really it's not going to go to court and the chances are that the individual then may not be arrested."
Savile, who died last year aged 84, had a bedroom at Stoke Mandeville Hospital, an office and living quarters at Broadmoor and widespread access to Leeds General Infirmary.
The NSPCC said it had received 439 calls about sexual abuse in the past three weeks, a 60% rise on what they would normally receive.