Presenter has been living in California city for a year and has produced films on terminal illness, sex offenders and feral dogs

Louis Theroux will return to BBC2 later this year with three new films promising to take viewers to the most "extreme parts" of Los Angeles.

The documentary maker and presenter, who was last on BBC2 in 2012, spent a year living in LA for the three documentaries, which will look at the treatment of patients with terminal illness at Hollywood's Cedars-Sinai Medical Centre, sex offenders after they are released from prison, and the way the city deals with neglected and feral dogs.

"I've been living in Los Angeles with my family for the past year or so. It seemed a chance to explore different sides of a single place, by spending longer immersed in stories and going deeper with the subjects," said Theroux.

"I have a love-hate relationship with the city. It embodies the best and worst of America. It combines wealth and glamour with social breakdown and deep neglect. We've concentrated on stories that take us into the extremes of life and the extreme parts of one of the world's great cities."

The three films will air on BBC2 in the spring and continue Theroux's focus on America since his When Louis Met … series came to an end in 2002, featuring Max Clifford, Neil and Christine Hamilton, and the late Jimmy Savile.

His US-based documentaries have included a look at neo-Nazis, the US prison system and The Most Hated Family in America, about a family at the Westboro Baptist Church, as well as a look at "extreme love", investigating the effects of autism and dementia.

Emma Willis, head of commissioning for documentaries across BBC1, BBC2 and BBC4, said: "Louis is one of Britain's most iconic interviewers and we're delighted that he's returning to the BBC to explore three diverse subjects in his own idiosyncratic style.

"In the 16 years that Louis has been making films for the BBC, he has produced some of our most challenging documentaries on a range of topics and we're fascinated to see where he'll take us next."

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