Paul Haggis (QMI Agency file photo)

Oscar winner Paul Haggis quit the Church of Scientology after 34 years because he was ashamed of becoming part of an organization he now considers a cult.

The Crash writer/director, who hails from London, Ont., has become the most famous and one of the most vocal former Scientologists, and on Thursday night he opened up about his time with the Church on U.S. news show Rock Center.

In his first TV interview about his former faith, he told newsman Harry Smith he walked away from Scientology because he was embarrassed by his links to the Church.

Haggis said, "I was ashamed of my own stupidity, of how I could have been so purposely blind for so many years."

And the filmmaker admits sitting down to talk about his feelings on TV is "incredibly stupid", adding, "These are not people you want to mess with."

He adds, "You've got these folks inside this fortress who won't look out and won't look at any criticism and can't bear the investigation and they think everybody is against them. How would you describe that? It's a cult."

Church of Scientology officials were well prepared for Haggis' TV appearance on Rock Center and released a statement to news show Access Hollywood before the programme aired. It read: "It is common knowledge in Hollywood that Mr. Haggis is one of the most arrogant and self-important persons that people have ever met.

"Paul Haggis has had no first-hand knowledge about the Church of Scientology for more than 30 years and the only information he has is hearsay."