LONDON: The head of the BBC said Tuesday that the scandal over alleged sex abuse by late star Jimmy Savile is “a very grave matter” that will affect the organisation's reputation for trust and integrity.

Director General George Entwistle, facing tough questioning from British lawmakers, said the BBC was doing everything in its power to find out how Savile was apparently able to carry out widespread abuse.

But he denied that the world's biggest public broadcaster put pressure on the flagship current affairs television show “Newsnight” to drop an investigation into the sex abuse claims late last year.

“There is no question in my mind this is a very grave matter indeed,”Entwistle told parliament's Culture, Media and Sport Committee. “One cannot look back on it with anything other than horror, frankly.”Savile, who with his jangling jewellery and shiny tracksuits was one of the biggest stars of BBC television and radio from the 1960s and 1980s, died last October aged 84.

The BBC's commercial rival ITV aired allegations about the entertainer by a handful of women two weeks ago.

“Newsnight” editor Peter Rippon announced Monday that he was “stepping aside” while the BBC carries out an inquiry into why the Savile item was axed.

The BBC has admitted that a blog post by Rippon, in which he said the Savile investigation was dropped for editorial reasons, was “inaccurate or incomplete in some respects” and had been corrected.

Entwistle himself is under pressure because he decided to proceed with a tribute to Savile over Christmas.

Asked if the scandal would affect the broadcaster's reputation for integrity, Entwistle said there was no question that it would “raise questions of trust”.

He said the “Newsnight” item on Savile should have been allowed to proceed.

But he defended the BBC's reaction to the scandal, insisting that the broadcaster was working closely with the police and that its own twin internal probes would thoroughly investigate what happened.

“I've been able to find no evidence ... that any kind of managerial pressure was applied. The decision was made by Peter Rippon on his own account,” Entwistle said.

He also defended the BBC's decision to air an episode of its main investigative television show “Panorama” dealing with the Savile scandal on Monday night.

The programme demonstrated the BBC's capacity to ask questions of itself in a way no other broadcaster in the world would do, Entwistle said.

The “Panorama” show included claims from a lawyer for some of Savile's alleged victims that there was evidence of a paedophile ring operating within the BBC during his heyday in the 1960s and 1970s.

Entwistle came under fire by lawmakers on the panel for apparently not knowing how many sexual harassment cases the BBC is currently facing.

But he insisted the BBC has much stronger procedures in place for dealing with sexual harassment and child protection than it did in the 1960s.

“I don't believe someone like Jimmy Savile could do what he was doing without there being a broader cultural problem,” he said.

Prime Minister David Cameron expressed concern Monday over the BBC's handling of sex abuse claims against Savile.

“The nation is appalled, we're all appalled by the allegations of what Jimmy Savile did, and they seem to get worse by the day,” he told reporters.

Entwistle has been the BBC's director general only since July.

Some lawmakers are calling for his predecessor Mark Thompson, who is due to start as CEO of The New York Times in November, to face a similar grilling in parliament.

British police have launched a separate criminal investigation into the alleged abuse by Savile.

Scotland Yard says it believes there may have been as many as 200 victims, and that it is investigating suspects linked to Savile who are still alive.