How Scientology keeps its secrets, and puts journalists 'on a par with sexual perverts'

The Church of Scientology is legendary for keeping a tight lid on its inner workings. In fact, its current leader, David Miscavige, hasn't done a TV interview in 25 years.

Still, for British journalist/documentarian Louis Theroux, who makes his living profiling the people living in the margins of society, Scientology was the, as he put it, "Holy Grail" of stories. That led to him making the documentary "My Scientology Movie" (currently in theaters, On Demand, and iTunes), which follows him as he travels to Los Angeles to investigate what goes on at the Church of Scientology's headquarters.

But it was quite a challenge at first to make a movie on the church with no access to anyone inside it.

"In 2002, we went through the proper channels and my producer at the time and I took a tour of the Celebrity Centre and then it all fizzled out," Theroux said, talking to Business Insider in a Facebook Live interview. "Eight years went by."

Theroux couldn't figure out how to do his kind of storytelling on the topic.

"I'm not just a reporter, I'm an experiencer of what's going on and we weren't going to do a backward story on how Scientology came into existence. It was to be an immersive piece about what it means to eat, breath, sleep Scientology," he said.

It also wasn't any help that Scientology has been hostile to journalists trying to glean insight about the organization, especially in recent years as questions about the church have ramped up. It has retaliated against projects like the HBO documentary "Going Clear" with smear campaigns.

"They don't let people in, they don't let reporters inside. And they view reporters as being what they call 1.1 on the Tone Scale, meaning on a par with sexual perverts," Theroux said, referring to the scale in Scientology that assesses a human's state.

"We just needed something to get the engine of the film going," the movie's director John Dower said of the block.

Then Theroux, Dower, and the film's producer Simon Chinn came up with an idea: retell the parts that Scientology was keeping from them.

"We came up with the idea of using actors to do reenactments of life inside Scientology," Theroux said.

"The first day of doing the auditions we had no idea if it was going to work and it kind of did," Dower said. They immediately found actor Andrew Perez to play the role of Miscavige.

They then brought on ex-Scientology executive Marty Rathbun to give insight on camera to Theroux and the actors doing the reenactments.

The movie ends up being the type of first-person storytelling Theroux is known for, even if it took extra work to get there. In fact, he even faced physical threats for his inquires into Scientology.

"It's a film within a film," Theroux said. "In life the line between performance and our real selves isn't always clear."

Watch Business Insider's entire Facebook Live chat with Theroux and Dower below: