Louis Theroux has expressed his regret at not being able to expose Jimmy Savile as a paedophile in his infamous documentary but remains "proud" of the programme.

Savile died at the age of 84 in 2011 as one of the nation's most beloved entertainers but less than two years later he was revealed to be one of the UK's most prolific paedophile sex offenders.

Theroux filmed an episode of his profile series When Louis Met... with Savile in 2000 in which his eccentric personality was on full display - and despite skirting around the industry rumours about his behaviour, the programme stopped short of a complete expose.

Asked by The Mirror if he regretted not being able to out Savile as a monster before he died, Theroux replied: "If you're asking, do I wish I'd made that programme and been able to expose him?

"I mean, it's a bit like saying, do I wish I could turn cheese into chocolate? Do I wish I could fly? Do I wish I could go back in time and predict the outcome of the World Cup and make millions of pounds?

"Do I wish I could go back and expose Jimmy Savile as a sex offender? Yeah, of course. If I did that story with a time machine and went back again, I would be armed with so much more information.

"But I really think that, given what we knew then, it's a piece of work that holds up.

"I'm still proud of that programme. I think that's a really solid piece of work, and I think of all the TV that was ever made about him while he was alive, that was easily the most revealing."

Theroux is looking back at some of his most memorable documentaries over the last two decades for a new BBC Two series, Louis Theroux: Life On The Edge, which starts on Sunday night.