PARK CITY, Utah - Alex Gibney’s new Scientology documentary stirred speculation that protesters might attend the film’s Sundance premiere Sunday night, especially after full-page Scientology ads appeared in the Los Angeles Times and The New York Times asking: “Is Alex Gibney’s Upcoming HBO ‘Documentary’ a Rolling Stone/UVA Redux?”

No protesters were outside the Marc Theater as Gibney’s film was about to start, but so many festival-goers turned up to see “Going Clear: Scientology & the Prison of Belief” that Sundance volunteers had to turn people away.

The film includes interviews with some former Scientology members who spoke to author Lawrence Wright for his 2013 book of the same name. “Going Clear” raises questions about the treatment of church members as well as the organization’s nonprofit, tax-exempt status.

A Church of Scientology spokeswoman called the assertions in the film “entirely false.”

“Despite repeated requests over three months, Mr. Gibney and HBO refused to provide the church with any of the allegations in the film so it could respond,” the church said Monday in a statement. The statement called Gibney’s sources “obsessive, disgruntled former church members” and said the filmmaker refused to speak to 25 people with “firsthand knowledge regarding assertions made in Mr. Wright’s book.”

The film, which will debut on HBO on March 16, focuses in part on two of the most famous Scientologists, Tom Cruise and John Travolta.

“Going Clear” recounts Cruise’s marriage to Nicole Kidman in detail. Marty Rathbun, a former high-ranking Scientology executive, says in the film that Cruise distanced himself from the church during his marriage to Kidman.

Rathbun alleges in the film that church leaders instructed him to “facilitate the breakup” of the couple. In response, Rathbun said Cruise was subjected to repeated audits with an e-meter, a device Scientology says measures one’s thoughts. Rathbun says in the film that he was sent transcripts of Cruise’s audits.

The filmmaker also claims that church executives threatened to release private information from Travolta’s auditing sessions if he ever quit the church.

Gibney said he is not worried about the church’s reaction to his film.

“I’m not scared,” he said. “I went to Afghanistan by myself - that was scary.”