Investigation: More than 500 child abuse reports made against BBC star Jimmy Savile

More than 500 reports of abuse on victims aged as young as two have been made against late BBC presenter Jimmy Savile, according to a new investigation by the NSPCC charity published Monday.

The probe found that Savile, one of the biggest TV stars in Britain in the 1970s and 1980s, exploited high-level contacts to gain access to vulnerable victims at a high-security psychiatric hospital.

"There's no doubt that Savile is one of the most, if not the most, prolific sex offender that we at the NSPCC have ever come across," said Peter Watt, director of child protection at the children's charity.

"What you have is somebody who at his most prolific lost no opportunity to identify vulnerable victims and abuse them."

The investigation was commissioned by BBC programme Panorama and will be aired at 8.30pm local time (1930 GMT).

The report uncovered government documents that showed a senior civil servant had pushed for Savile to be appointed as head of a task force to resolve a dispute between trade unions and management of the Broadmoor psychiatric hospital in southern England in 1988.

Thames Valley Police says it has now received 16 reports of abuse by him inside the special hospital, for which he had his own set of keys.

- Savile 'swapped autographs for kisses' -

Former Broadmoor manager Trevor Smith said Savile would give young girls autographs in exchange for a kiss.

"He kissed these girls who were about 13 smack bang on the lips, held his hand behind their neck to pull them forward and he virtually was giving them French kisses," he explained.

Savile, who died in October 2011 at the age of 84, was a hugely popular but eccentric figure, famed for his shock of white hair, tracksuits and chunky gold jewellery. He was knighted in 1990.

He used his fame as presenter of BBC TV's "Top of the Pops" chart show and children's programme "Jim'll Fix It" to rape and assault victims on BBC premises as well as in schools and hospitals, where he was welcomed by his fans.

The latest NSPCC figures show the most common age group for Savile's victims was between 13 to 15.

A year after his death, five women went on television to complain Savile had abused them when they were girls, opening the floodgates for hundreds of similar allegations.

An joint NSPCC and police report published last year gathered claims from around 450 people, detailing 214 criminal offences, including 34 rapes -- 28 of them of children.

The scandal threw the BBC into crisis and its botched handling of the fall-out led to the resignation of director general George Entwistle in November 2012.

It has commissioned an independent review into the culture and practices of the BBC during the years that Savile worked there.

"The BBC has said it is appalled at Jimmy Saville's crimes," a BBC spokesman said in response to the new report.

"We're unable to give a commentary on statements in these specific documents as they are over 40 years old, but the Dame Janet Smith review is considering the culture and practices of the BBC during this period and has had our full cooperation. We will await their full report."