Vimeo acquired exclusive U.S. first-window download-to-own rights to documentary “Going Clear: Scientology and the Prison of Belief,” from filmmaker Alex Gibney.

The film will be available on Vimeo On Demand in September 2015 following HBO’s broadcast window; HBO is slated to debut the docu March 16. Pricing for the “Going Clear” on Vimeo has not yet been determined.

The documentary — which premiered last month at the Sundance Film Festival — is based on Lawrence Wright’s 2013 bestselling book of the same name. “Going Clear” profiles eight former members of the Church of Scientology, exploring the psychological impact of blind faith, how the church attracts new followers and how it retains its A-list celebrity devotees.

For Vimeo, the Internet-video service owned by IAC, the film fits into its history of attracting indie film projects to its platform.

“‘Going Clear’ offers an in-depth look behind the curtain of one of the world’s most mysterious and controversial religions,” said Sam Toles, Vimeo VP of content acquisitions and business development. “This film represents the level of extraordinary, top-quality programming that audiences have come to expect from Vimeo On Demand.”

Gibney’s film takes a broad look at the controversial and secretive Church of Scientology, including founder L. Ron Hubbard, its celebrity recruiting efforts and alleged abuses by church officials. The church has disputed the claims made in the book and the film, labeling the interview subjects as “the usual collection of obsessive, disgruntled former Church members kicked out as long as 30 years ago for malfeasance, who have a documented history of making up lies about the Church for money.”

The Vimeo deal was negotiated with Content Media Corp., which owns a 50% stake in Gibney’s Jigsaw Prods.