Several months before it was scheduled to be seen on premium cable by a large national audience, the Church of Scientology took preemptive action against “Going Clear: Scientology and the Prison of Belief,” a documentary exposé directed by Alex Gibney, which premiered on HBO March 29 after opening theatrically in New York, Los Angeles and San Francisco March 13.

The program is set to air again tonight, March 30, on HBO at 9 p.m. ET/PT, with additional airings on HBO and HBO2 to follow. (See note at the bottom of this story.)

The feature-length film was an official selection at the 2015 Sundance Film Festival and is based on the best-selling book by Lawrence Wright.

Try Googling the title, and the first thing that pops up is an official-looking website run by Scientology that questions the entire veracity of Gibney’s documentary. The same thing happens when you search for Wright’s 2013 book, whose title is slightly different, “Going Clear: Scientology, Hollywood and the Prison of Belief.”

The Church also took out full-page ads in The New York Times and the Los Angeles Times that slammed “Going Clear” after it screened at Sundance.

The film traces the history of Scientology’s origins, which sprang from the mind of science fiction author L. Ron Hubbard and went on to attract a slew of bold-faced Hollywood names — which contributed to its popularity all over the world.

A rare interview with Hubbard, a long-lost piece of archival footage including outtakes from an interview with Granada Television, gives viewers insights into the charismatic and controversial leader. Hubbard, who died in 1986, developed the doctrine and rituals of Scientology in the years after his wildly popular “Dianetics” self-help book was published in 1950.

There is also revealing footage of recent Scientology pep rallies, led by David Miscavige, the church’s enigmatic leader and chairman of the board of the company that controls the trademarks and copyrights of Dianetics and Scientology.

But the main focus of the documentary is interviews with eight former Scientology members, including Oscar-winning screenwriter Paul Haggis, who describe their experiences in harrowing detail.

The revelations are shocking as they describe a systematic history of abuse and betrayal that they contend goes on to this day, sanctioned by the current leadership of the church.

“The way that they could not see what was happening to them was what moved me the most,” says Gibney. “And their recollections of the slow pain of recognition as they realized that, to leave the prison of belief in which they were trapped for so many years, they had only to open their minds. But that was so hard to do.”

Contrasted with those experiences, the film also describes the ultra-VIP treatment given to Tom Cruise, the church’s best-known adherent, and delves into the dissolution of his marriage to Nicole Kidman. It also looks at the grooming of actress Nazanin Boniadi, a former Scientology member best-known for her recent role as a CIA analyst in “Homeland,” as his girlfriend.

Gibney has an extensive directorial history of chronicling controversial subjects, including Lance Armstrong, Julian Assange and Eliot Spitzer. His last documentary for HBO was 2012’s investigation into sex abuse and pedophilia in the Catholic Church, “Mea Maxima Culpa: Silence in the House of God,” which won two Emmy Awards and was nominated for a third.

As to how the two subjects compare, he said, “Scientology was less grim, to be honest. Raping deaf children — and covering it up — is about as dark as a story can be. But what was interesting about this film was doing a deep dive into the psychology of belief.”

Gibney, who won an Oscar for another documentary, “Taxi to the Dark Side” (2007), and was nominated for 2005’s “Enron: The Smartest Guys in the Room,” is not surprised by Scientology’s reaction to “Going Clear.”

“But in stepping back and looking at it, I am amazed at how a so-called ‘church’ can invoke so much vitriol and hate. Hate is a powerful narcotic that numbs the pain of doubt. But it is also addictive. And it is on that the church depends. So much of the church’s reaction — which is mostly angry attacks on me, Larry [Wright] and especially those in the film — is actually meant to feed the addiction of the members. The hate is for them. I hope they can kick the habit.”

Still, he remains hopeful about mitigating the level of hostility. “Someday, I would hope that the current members and clergy who seem so fond of vitriol can look, with ‘clear’ eyes, at the love and empathy that the ex-members have found after leaving the church. As MLK once said, ‘Hate cannot drive out hate. Only love can do that.’”

(“Going Clear: Scientology and the Prison of Belief” airs tonight, March 30, on HBO at 9 p.m. ET/PT and on April 1, 5, 9, 11 and 17. Check local listings for additional HBO2 playdates April 2, 4, 8 and 16.)