The allegations came as two more alleged victims of Savile came forward. Four police forces have now received complaints against the late Top of the Pops host.
The Association of Chief Police Officers says Britain’s national child protection unit CEOP is to assess the scale of the allegations.
It follows the screening of a documentary about Savile on ITV on Wednesday.
Historic accounts detailed how the presenter allegedly targeted girls in his BBC dressing room and private Rolls-Royce.
In the programme, a woman claimed she was raped when she was 13 in his dressing room at the BBC Television Centre.
The attack, in the 1970s allegedly took place as Savile was groping a 14-year-old in the same room while a third star — a well-known entertainer — was abusing a schoolgirl, according to the claims.
The allegations were made by Karin Ward, a former pupil of the Surrey school where Savile is accused of preying on under-age girls.
She waived her anonymity to tell the documentary how the Jim’ll Fix It star was working with musician Glitter.
Ms Ward said she was abused when she and two fellow pupils of Duncroft boarding school for emotionally disturbed children, were invited to London by Savile. She said they were taken to his dressing room.
“I saw Gary Glitter have sex with a girl in Jimmy Savile’s dressing room... in that little alcove bit. I didn’t see it completely but that’s what was going on and nobody batted an eyelid. Jimmy Savile had a girl on his lap and he had his hand up her skirt.
“The girl Gary Glitter was having sex with also came from Duncroft. I think she might have been not quite 14.”
She said the third star tried to grope her.
“It frightened me and freaked me out. He humiliated me in front of everyone in the dressing room by saying something really unkind about my lack of breasts.”
The star was not named by ITV and yesterday denied the allegations when confronted by reporters.
Surrey Police has also confirmed it investigated Savile over abuse claims in 2007, but dropped the case due to a lack of evidence, while Jersey and Sussex Police said they had both received complaints about the star. Scotland Yard said last night it was also assessing a small number of other allegations.
The BBC said it will assist police with investigations into the child abuse claims.