Louis also continues to write for print publications. In 2005 he published a travel book about a few of his adventures, The Call of the Weird.

Over the years, Louis has kept true to a way of working that is uniquely his own: by charming his subjects, he’s able to offer rounded portraits of some of the world’s most psychologically gripping issues, while always resisting easy judgements. Louis has won two BAFTAs, an RTS award, and a Bulldog award, not to mention numerous nominations.

In 1995 the BBC signed Louis to a development deal. He came up with an idea for a documentary series that would follow him as he immersed himself in off-beat lifestyle, called Weird Weekends.

Louis graduated from Oxford in 1991 and started out as a print journalist the following year, working for Metro weekly in San Jose and then in New York for Spy magazine. He got his television break from Michael Moore, who hired him as a writer and correspondent for his ground-breaking satirical show, TV Nation.

In the course of his career, Louis has scored a number of journalistic scoops. His series of celebrity profiles, When Louis Met…, took viewers inside the world of the charity fund-raising eccentric Sir Jimmy Savile; the media guru Max Clifford and his client Simon Cowell; and most famously Neil and Christine Hamilton, who found themselves the subject of rape allegations during filming and allowed Louis and his director to continue to stay with them and document the ensuing media onslaught.

Over more than 15 years, using a gentle questioning style and an informal approach, he has shone light on some of the world’s most intriguing beliefs, behaviors, and institutions by getting to know the people at the heart of them – from the officers and inmates at San Quentin prison to the extreme believers of the Westboro Baptist Church; the male porn performers of the San Fernando Valley to the medical regime in one of America’s leading centers of mental health for kids. Recently he made a two-part series on Miami county jail and a special on America’s private menageries of exotic animals.

Louis Theroux is a BBC television presenter best known for making documentaries that investigate fascinating worlds and lifestyles. His latest work is a feature documentary on the Church of Scientology, My Scientology Movie, released in the US in March 2017.

Louis Theroux: I remember first to hearing about it from my uncle Peter who lives in Long Beach, and when I visited him in L.A. for the first time he told me about this religion that had been created by a sci-fi writer called L. Ron Hubbard, and that it was beloved of actors and celebrities, and that they used hard sales tactics. (These were all his allegations; I mean I'm sure Scientology would deny it.) And that they were very secret, no one really knew what was going on inside.

And in fact he told me—I remember him saying, “You can go down and look at their base; they've got walls around it with spikes on, but the spikes don't face outward…the spikes face inward.” And I thought all of this was sort of really appealing. I mean my own sense of both the absurd but also the macabre was massively piqued.

Scientology to me seems to be a kind of junction of so many quintessentially American qualities. You've got the celebrity dimension; you've got the fact that it's in Hollywood; you've got its sort of relation to the business world and its swash-buckling form of capitalism that we have in the U.S. where you find a need and you market to it, and if the need doesn't exist then you create the need.

To me it's always very telling when you realize that basically McDonald's and Scientology came into existence at almost exactly the same time. Around about 1950 Dianetics was published and the first McDonald's was established. And actually as business models they're rather similar in they both work using a franchise system. And to me Scientology is selling the spiritual hamburgers, if you like.

But it’s this piquancy that's added to it because of the strangeness and humor that's wrapped around it, you know, the bizarreness of the language and the ritual. The packaging is to me quite funny.

At the heart of Scientology is a kind of contradiction, which is that they want to spread the good news about Scientology and Dianetics, that it’s a life-changing, life-saving system that allows you to be your best, and in fact more than that is our last, best hope for saving the planet from war, insanity, crime, intolerance, and so forth.

But they also don't want to give up those secrets too easily either, because they would say you have to go through a certain path, and that takes a “Bridge to Total Freedom,” as they call it.

But actually arguably it's because it's their business model to sell secrets. So the contradiction is, well how do you market a secret? And unlike other religions that I can think of, Christianity—you can get a Bible, in any hotel room you'll find one in the top drawer of your bedside table. And Islam, Buddhism, Hinduism, all the major religions as far as I'm aware, their sacred texts are freely available, and there aren’t a whole bunch of secrets, you know, origin stories or mysterious myths, that you have to pay to learn. “Well what's inside the box? What could it be?”

And they also regard outsiders, and particularly journalists, as enemies. To me, it's actually both a problem in as much as they're not giving access, but it's also massively appealing and tantalizing to be aggressively confronted and then turned away.

Unlike most religions that you think of as being sort of welcoming, and ethical, and in the normal way where they sort of invite you—“Come on in, film with us, we'll tell you what we do”—Scientology is constantly, it seems to me, kind of pushing you away and telling you that they don't want your coverage. That nothing you can say about them is going to be the truth.