Louis Theroux on his best moments and biggest controversies

As the BBC looks back at his 25 years of documentaries, film-maker Louis Theroux reveals why he decided to stop making fun of people and get serious. Photo / Getty Images

Louis Theroux turned 50 during lockdown, and had his bicycle stolen. He's only just got a new bike, he tells me, when we meet via computer screen, and he's going to be much more careful with it.

As for the "big milestone", he was psychologically prepared for it, although it did have him thinking about his father, the American writer Paul Theroux, who turned 50 when Louis was in his final year of university.

"I suppose I would have thought of him as pretty old," he says.

He's at a different life stage to his dad, though, he explains, as his children are much younger. He and wife Nancy Strang have three boys between the ages of five and 14 – "I'm a happy sort of family man," he says.

He's a busy one, too. During the months stuck at home in north London he's made a podcast series, interviewing guests such as Boy George and Helena Bonham Carter, plus an insightful, entertaining (and about-to-air) four-part look back at the programmes he's made over the past 25 years, Louis Theroux: Life on the Edge.

Each episode examines a different theme: crime; religion and fanaticism; "the dark side of pleasure" (including films on drugs, pornography and gambling); and "family ties" (spanning issues such as adoption, dementia, autism and transgender children).

From a personal point of view, it has highlighted the way he has changed as an interviewer, he says. "In the early days, it was absolutely the case that I would try to send people up by, in a wide-eyed way, agreeing with crazy things," he admits.

He is surely thinking of films such as his 1998 one about Ufologists, in which he meets Thor Templar of the Earth Protectorate, and asks questions such as "This is scientific?" when shown some "25th-century technology" to guard against aliens.

"I was just out to give them enough rope and hope that they would end up looking ridiculous. But I think over the years I gradually evolved into this different creature."

Certainly, it was a subtly changed presence who engaged with Gus and Deborah – both of whom had chosen to end their own lives – in 2018, one that is undeniably caring and understanding.

Of course, Theroux's gift is to be friendly and disarming even among first-degree murderers and hate preachers like Kansas's Westboro Baptists, whom he joined as they picketed the funerals of soldiers killed in Iraq with placards proclaiming their deaths as God's punishment for America's tolerance of homosexuality.

Being objective "comes naturally", he says. "I have to work my way into a more confrontational mode."

He does get into the odd "ding-dong", he adds, but usually when he has "skin in the game", such as when a woman kept accusing him of trespassing when he was shooting My Scientology Movie in California.

"I was personally rather offended because I felt that I hadn't trespassed. She said, 'You have and I'm calling the police.' I noticed an unfamiliar sensation, which was irritation on my part."

And of course, a number of interviewees who have been won over by Theroux have later regretted it. In the final episode of the new series, he reads out a missive from the Westboro Baptists' (now dead) founder, Fred Phelps, which takes aim at his "cutesy little endearing qualities, feigned humility… pretended befuddlement", to which Theroux adds, "He kind of nails it."

That is his interviewing technique in a nutshell, though, isn't it? "I was being a little bit facetious," he says. "I am quite socially awkward [and] I disagree on the 'pretended'."

As well as a change in style, there has been a change of emphasis: more serious topics, more willingness to enter into people's trauma, be that dementia or wanting a child.

But was the faux-naïf of his early films really just naive? His glimpse inside the world of Jimmy Savile, When Louis Met Jimmy, seemed like a career-high point when it aired in 2000, more than a decade before it became clear, after Savile's death in 2011, that the DJ had been a rapist and sexual predator on an almost unimaginable scale.

I wonder whether he feels that programme was his biggest failure; that he should have probed further? "The thing is," he says, "a big part of how [Savile] was able to get away with his offending was that he was sort of impervious to negative attention, and capable of brazening out any kind of inquiry or interrogation.

"I think you could just as fairly say of that documentary that it was a remarkable piece of work and got closer to the truth than any other piece of television while he was alive, so it doesn't feel like a failure."

He also made a film about Michael Jackson, against whom serious allegations had been made a decade earlier, and who had defended sharing his bed with children to Martin Bashir earlier that year.

Theroux's film ends with him saying: "The truth is I'd love to meet him, not to ask questions about why he is the way he is… but simply to enjoy being with him, another curious bystander and fan."

After the shocking revelations in last year's Leaving Neverland, does that make him cringe a little now? "Um, well, I would say this," he begins, "that I'm still a fan."

Theroux has no doubts about the singer's sexual pathology. "If you can't see that Michael Jackson was a paedophile after watching [director] Dan Reed's film you are being willfully blind," he wrote on Twitter.

"I am able to separate the life and the work," he says. "How could you not be a fan of the music, especially the earliest stuff? I still think that people who have been guilty of terrible crimes can create incredible work."

On an adjacent point, he has no time for those on Twitter who say you can't listen to Elvis Presley because he co-opted black music. "It is very rare for serious and sensitive social and cultural issues to be sorted out on Twitter," he says in his typical deadpan way.

Theroux, fortunately, is not likely to be "cancelled" any time soon, although we may be seeing less of him. He's working with Strang on ideas for long-form series in which he is not on camera.

But he's quite good at avoiding controversy, like when I ask him, as someone who made a sensitive documentary in 2015 about children transitioning from the gender they were born into, what his thoughts are on the trans debate that exploded with J K Rowling's remarks on Twitter.

He tries to avoid "slipping into generalities like, 'This is good, this is bad' ", Theroux says. "It turns out I'm not terribly opinionated in general." Very wise.