BBC chief testifies in TV presenter Jimmy Savile abuse scandal George Entwistle calls the Jimmy Savile case "a very, very grave matter" The BBC's handling of the child sex abuse scandal is under scrutiny by lawmakers Police say they have identified more than 200 potential victims of Savile "This is the worst crisis I can remember at the BBC," says veteran BBC correspondent London (CNN) -- The head of the BBC sought Tuesday to defend its handling of a scandal involving sex abuse claims against a late children's TV presenter and DJ -- including why the broadcaster decided to drop an investigation into the star last year. BBC Director General George Entwistle faced tough questions from British lawmakers over the BBC's response to the allegations against Jimmy Savile, a household name in Britain, and its broader culture. He acknowledged that "what we now know happened is a very, very grave matter indeed." But, he said, "we have done much of what we should have done." A slew of accusations against Savile emerged over the three weeks since a rival broadcaster released a documentary in which five women alleged abuse, some of it on BBC premises. London's Metropolitan Police last week said more than 200 potential victims had been identified, and labeled Savile a predatory sex offender. A criminal investigation has been launched into claims of abuse by "Savile and others," many of which date back to the 1960s and '70s. While Savile cannot be prosecuted, the police said, "what we have established in the last two weeks is that there are lines of inquiry involving living people that require formal investigation." The furor has shocked a generation of Britons who grew up watching Savile, one of the most recognizable figures in British showbiz from the 1960s to the 1980s, or listening to his radio shows. The scandal has also gripped the British media, with many questioning who knew what and when about the alleged abuse of teenage girls -- and risks lasting damage to the reputation of the United Kingdom's public broadcaster. Lawmakers on Parliament's Culture, Media and Sport Committee pressed Entwistle over the impact of the furor on public confidence in the BBC. Their questions are focused on two independent reviews set up by the BBC -- one into its handling of its own investigation into Savile last year, and the second into the culture and practices of the broadcaster, during and after Savile's time there. Entwistle said the BBC is working with the police and has sought to ensure nothing it does would compromise the investigation into "what the police describe as an unprecedented child exploitation." He was criticized by lawmakers over his inability to answer detailed questions concerning whether there are current sex abuse claims at the BBC. "There is no question that what Jimmy Savile did and the way the BBC behaved in the years -- the culture and practices of the BBC seems to allow Jimmy Savile to do what he did -- will raise questions of trust for us and reputation for us," Entwistle responded. This is a gravely serious matter and one cannot look back at it with anything other than horror, frankly, that his activities went on as long as they did undetected. The BBC's "Panorama" program broadcast its own probe into the "Newsnight" decision on Monday evening, suggesting serious allegations had been made to "Newsnight" reporters before the investigation was shelved. Entwistle said he was given no oversight over Panorama's broadcast because it was looking into senior BBC management figures. But having watched the program, he said, he was "surprised that nothing further happened" in light of the material dug up by "Newsnight." Key questions relate to whether the "Newsnight" decision was connected in any way to the BBC's plans to run tribute programs looking back at Savile's charitable work, broadcast last Christmas. The former head of Sky News is carrying out a review into the management of the "Newsnight" investigation. The BBC's veteran world affairs correspondent John Simpson gave an idea of the sense of disarray within the widely respected broadcaster in an interview broadcast Monday. This is the worst crisis that I can remember in my nearly 50 years at the BBC. ... I don't think the BBC has handled it terribly well. All we have as an organization is the trust of people, the people that watch us and listen to us. ... If we start to lose that, that's very dangerous for the BBC. Savile was the first host of the BBC's hugely popular "Top of the Pops" music show, and his own program, "Jim'll Fix It," ran for almost 20 years.