The BBC's new director general, George Entwistle, broke his six-day silence over the Sir Jimmy Savile abuse allegations to say he was appalled by the torrent of revelations from victims. But he insisted there was no evidence to suggest that "any known wrongdoing was ignored by management" in the 1960s and 1970s.

He said it was not necessary for the BBC to launch an independent inquiry because, having consulted the Met and other police forces examining allegations, that would "run the risk of damaging or impeding their work".

Entwistle said: "The police are the only people with the proper powers to assess criminal allegations."

There are now thought to be more than 40 allegations of abuse by Savile.

The Met, which is leading the Savile investigation, said it was "collating information" and working closely with the BBC following a meeting on Friday morning. The force said it did not expect to have a clear picture of how many women may have suffered abuse until next week and an assessment of the evidence would take some time.

In his email to staff, released at 5.40pm on Friday, Entwistle also addressed last year's decision to axe a Newsnight investigation into abuse by Savile. He said the editor of Newsnight, Peter Rippon, decided "honestly and honourably" in December not to broadcast the planned 10-minute film – and he had seen "no evidence" that pressure was applied on him by any other part of the BBC.

At the time, the BBC was preparing a Christmas special dedicated to Savile and there was a belief at Newsnight that the decision to drop the film may have involved other executives. At the time Entwistle was the BBC's director of vision, but press sources denied he was involved.

While the comments from Entwistle may be the first time he has spoken out about the Savile affair, they did not amount to a change in the BBC's position. He reiterated that, "crucially and regrettably", there were "no complaints … made at the time" and there was "nothing at this stage to suggest any known wrongdoing was ignored by management".

That contrasts with repeated assertions by people who encountered Savile while working in the music and entertainment industry that the sexual proclivities of the DJ and presenter were well known or at least widely speculated upon.

This week household names such as Paul Gambaccini and Janet Street-Porter were among those who said they were aware of his interest in teenage girls and young women.

Chris Poole, who worked at Decca Records in the 1970s, said he was "amazed it hadn't already come out" but added that Savile's alleged habits needed to be set in the context of a highly sexualised era in which many forms of activity and behaviour now regarded as dubious were considered commonplace. He said there were rumours about many DJs, musicians and music executives at a time when a so-called groupie culture was more acceptable.

Also connected with Decca at that time was Jonathan King, who ran his own record label and presented TV and radio shows, and was jailed in 2001 for sexual offences against minors.

Chris Denning, a former Radio 1 DJ, has been jailed several times for offences relating to child pornography and gross indecency, most recently in Slovakia for five years in 2008.

A former Radio 1 DJ who asked not to be named said the context of the time was different; it was after the arrival of reliable contraception and before the emergence of the Aids virus. Overt sexual behaviour was common. "It was a unique 25-year period in human history in which it was possible to have sex without endangering yourself and people took advantage."

Trevor Dann, who was a Radio 1 producer between 1979 and 1983, did not work with Savile but said he knew the DJ was "one of those people that would be gossiped about" and people at the station told stories about "Jimmy and young girls".

He said that it would have been difficult for junior staff to make a complaint. "If I had gone to one of my bosses and said 'this is what I've heard about Jimmy in the pub' then they would have told me to grow up. I'm not saying that the BBC was complicit, but everybody is more accountable now than they were then," Dann, now an independent radio producer said.

There is little surprise that it was possible for Savile to take advantage of his celebrity. "If you pleased Jimmy, he could have chosen you to appear on camera on Top of the Pops with him. Remember how the DJs were surrounded by fans," Poole said.