Louis Theroux has forged a career interviewing wacky fanatics and weird extremists, but the award-winning documentarian concedes far-right groups have now become more insidious than ridiculous.

Key points: The award-winning filmmaker will tour Australia in January next year

The award-winning filmmaker will tour Australia in January next year The show will cover topics including sex-trafficking and religious extremes

The show will cover topics including sex-trafficking and religious extremes He says he would love to spend some serious time in Australia for documentary work

"They have been risible, and I have regarded that as one of the reasons it's been acceptable to talk to them," he told the ABC.

"There's a sort of nativist, or what they call ethno-nationalist politics, that's become mainstream political discourse and I think that's worrying."

The award-winning filmmaker will share many of his worldly experiences when he returns to Australia early next year for his upcoming live stage tour.

He will delve into subjects from his catalogue of documentary work around the world, from sex trafficking to religious extremes.

Never one to shy away from poking some fun at fundamentalists, Theroux cautioned his future interviews with extremists would require alternate tactics.

"It demands a different approach and a different way of thinking about it," he said.

"I'd like to think it's still within the scope of my journalism to look at it, but it's a slightly different scenario."

Louis Theroux during his time filming the LA Stories series. ( Supplied )

AFP raids 'an occasion for fearfulness'

Theroux labelled the Australian Federal Police raids on the ABC headquarters in Sydney and the home of News Corp journalist Annika Smethurst as "an occasion for fearfulness".

AFP officers and computer technicians raided the headquarters this month with police searching all documents that might be related to a series of 2017 stories known as The Afghan Files.

"I found it quite worrying, because as a journalist myself the freedom of the press is deeply important and it's got to be a bad sign for any democratic society," he said.

"My respect goes out to any journalist who is involved in the reporting of the stories.

"I encourage them [journalists] to regard it as a feather in their cap and a mark of distinction that their work's important enough to attract the attention of the authorities."

He drew similarities between the AFP raids and the intimidation he experienced firsthand while filming his documentary on the secretive and salacious Church of Scientology.

"I remember when there were times when I was very, very worried because of things that Scientology were doing in an attempt to shut me up and that pales in significance at the idea of … [the] police force raiding you and your headquarters, rifling through your files and going onto your computer," he said.

Strong indication on Australian documentary

The bashful Brit has frequently flirted with the idea of filming a documentary down under, but he has now given his strongest indication that an Australian exposé is on the cards.

Louis Theroux with a prisoner during filming of his LA Stories series. ( Supplied )

"I would love to come and spend some serious time there with the family," he said.

"My dream scenario would be me and my wife and the three kids living in Australia while I pursued some Australian subjects, which would obviously involve a bit of upheaval but I'm still hopeful that my wife Nancy might go for it, so I'm working on that."

He said travelling to Australia's "interior" to explore the outback and the plethora of problems faced by Australia's Indigenous community was a firm focal point.

"The price that's been paid by Australia's Indigenous community for Britain sending so many people over there has obviously been absolutely immense," he said.

"I'm sort of interested in the way in which different cultures intersect and also the post-colonial experience."

When asked about the country's Indigenous youth suicide crisis, Theroux said it sounded "absolutely horrendous" and was a topic he would research further.

"I hadn't heard about that, I'm ashamed to say, and I will be looking it up," he said.

"The idea of any child killing him or herself is just beyond awful and I can't begin to imagine what the level of dysfunction and sadness and abuse and lack of opportunities might be behind that."

Theroux will begin his Australian talking tour Louis Theroux Without Limits to be hosted by Julia Zemiro in January next year and will visit Perth, Adelaide, Canberra, Brisbane, Sydney and Melbourne.