Producer Simon Chinn, presenter Louis Theroux and director John Dower at the London Film Festival premiere of My Scientology Movie (2015)

Given the controversy unleashed by Alex Gibney’s Going Clear: Scientology and the Prison of Belief, there’s every reason to expect sparks to fly at the April 17 international premiere of John Dower’s new documentary My Scientology Movie and its post-screening Q&A at the Tribeca Film Festival.

“I’d love for someone from the church to come see it,” Dower told The Hollywood Reporter. “I don’t think any of them have seen it yet. You know, hold your judgment. You might be surprised.”

The film follows Louis Theroux — a guerilla-style BBC journalist who has been dubbed Britain’s Michael Moore for taking viewers inside bizarre American subcultures like militias and the porn industry -- in his quest to understand the psyche behind the average Church of Scientology member.

Theroux enlisted ex-members like former top-ranking Scientology exec Marty Rathbun to tell their stories. But he and Dower also needed people to stand in for leader David Miscavige and acolyte Tom Cruise, so actors were hired to portray them. While Dower was shooting footage in 2014, Scientolgists -- presumably tipped off by the audition call -- showed up and turned the cameras on Theroux and Dower.

“They have a reputation for following you and filming you, but we honestly didn’t expect them to do what they did,” Dower said.“They said they were making a documentary about Louis, so it all started to get a bit strange. We were making a film about them and then they started making a film about us and tailing us and filming us. We’ve still not seen their film on us, but I’m intrigued to see it. I don’t know when they’ll release that. Maybe they’ll bring it out as the same time as the film in Tribeca.”

During filming, Dower and Theroux also learned that Gibney’s project was in the works. But Gibney was making a traditional historical film about the church and Dower and Theroux were aiming for something more in the vein of Monty Python than Mike Wallace.

“Going Clear is a great film, beautifully made, really well crafted,” Dower said. “If you know nothing about Scientology, it really does tell the story very well. But we wanted to make something that was different, what it might to actually become a Scientologist. We didn’t set out to mock at all. We genuinely set out with the intention of trying to understand why people [embrace] the wackier elements, the Xenu overlord, this kind of alien creature. And we were like ‘How is that different to angels and Christian beliefs?’”

Nevertheless, that didn’t stop the harassment or the legal challenges. The film, produced by BBC Films and Simon Chinn's London-based Red Box Films, which has produced such docs as Man on Wire and Searching for Sugarman, had its world premiere at the London Film Festival in October. But because libel laws are stricter in the U.K. than in the U.S. (consider that the publication of the book Going Clear was held up for three years in the U.K. and was only just published last month), Dower had to walk a fine line to get the film past the BBC’s internal censors (the film is scheduled to air on the British network after a theatrical run).

“We had to stand up our film much more [than Going Clear], and we had a much more lengthy process with the church. But it was encouraging that the London Film Festival put it out," Dower said.

Still, the film's inclusion in the London fest prompted a letter from Scientology lawyers objecting to the way the film had been written up in the festival's brochure, a complaint that Dower found to be over the top given that the filmmakers had nothing to do with the wording.

"This is probably the only film I’ve done at this level of litigiousness," said Dower, whose previous documentaries include The Last 48 Hours of Kurt Cobain and the boxing-themed Thrilla in Manila. "Scientology seems to threaten a lot, and then nothing ever really happens. You get these long, detailed letters in which they object to what you’re doing, and they’re very threatening but then nothing." He laughs, "I could regret saying that, I guess."

As for the legal team behind My Scientology Movie, it was a small contingent compared to the 160 attorneys that HBO used to vet Going Clear.

“Sadly, we didn’t have 160,” Dower joked. We had one of our own, and we had a couple at the BBC. But, you know, we’re English. We like to keep it simple and straightforward.”

The Church of Scientology did not yet respond to THR's request for comment.