300 alleged Jimmy Savile victims have contacted police since ITV documentary

Head of Scotland Yard inquiry says case is 'watershed moment for child abuse inquiries'

Three hundred people have come forward to the police alleging that they were abused by Jimmy Savile – all but two of them women – since the first allegations were aired three weeks ago.

Commander Peter Spindler, who is leading the Scotland Yard inquiry, said coverage of the affair had "lanced the boil" and that the case was proving to be "watershed moment for child abuse investigations".

It has emerged that police officers from at least four forces were aware of allegations against Savile – which included attacks on girls at an approved school in Surrey and at Stoke Mandeville hospital – but they did not lead to any prosecution. Sussex Police has confirmed that it dropped an inquiry in 2008 into allegations against Savile after his accuser declined to take the case further. Savile's name also emerged during an inquiry into the abuse scandal at the Haut de la Garenne children's home in Jersey from the 1970s but he was never questioned.

It was not clear if Savile was ever interviewed over an allegation investigated by Scotland Yard in the 1980s about an incident in a caravan, revealed by a retired police officer yesterday. Commander Spindler said that officers were trying to find the file on the case.

News of that investigation came after another woman told a BBC radio programme that she had been raped in the caravan in 1970. She said that she reported the attack, when she was aged 22, to police and the BBC this month.

Rob Wilson, the Conservative MP, said: "It appears that these events were taking place on BBC premises by someone employed by the BBC but, despite the rumours, nobody there felt it necessary to take these matters to the police. It now appears even when it was reported by some of those people affected they weren't taken as far as a prosecution. We need to know why that happened."

Police are preparing to carry out the first arrests of people named in the inquiry. So far police have spoken with fewer than half of the victims and recorded 114 allegations, most of them linked to Savile, but including others who might have acted with him.

"We have to believe what they are saying because they are all saying the same thing independently," said Commander Spindler. "There's Savile on his own, and that's the vast majority of what we're being told about; there's Savile and others. And it's the others, if they're living, we can look at."

Commander Spindler said there was no evidence of a paedophile ring. But he said that one of Savile's former properties in Scotland had been searched to discover any evidence that might link other people to attacks there.

Commander Spindler said he hoped the case would prove to be a "stark warning to any men out there today who think they can exploit their positions of power and influence and abuse children and young people in Britain."

Asked if the Corporation had been aware of the police investigation in the 1980s, a BBC spokesman said in a statement: "These allegations are being dealt with by the police."