Once a loyal member of the Church of Scientology, Leah Remini is opening up about her split from the church and one of the best-known Scientologists: Tom Cruise. Remini spoke with 20/20's Dan Harris about her new tell-all book, Troublemaker: Surviving Hollywood and Scientology, and experiences she had with Cruise.

"At first it's very effusive, it's very loving. You get the, like, laser in on you and you're the most important thing that ever happened," she said of how she first crossed paths with Cruise, who was friendly and supportive.

Remini recalls how she began to realize Cruise's stature within he church after Scientology officials asked her and her husband to teach the actor salsa dancing. When she arrived, officers were there to monitor the lesson, as well as his then girlfriend Katie Holmes. After commenting on Cruise's overly enthusiastic affection for Holmes, Remini was written up for being critical of Cruise and the church.

Former Scientologist Leah Remini shows support for HBO's Scientology Doc Going Clear

In response to Remini's book and interview, Holmes provided a statement to People, saying, "I regret having upset Leah in the past, and wish her only the best in the future." It is not yet clear what Remini alleges about Holmes, who was married to Cruise for nearly six years before divorcing him in 2012.

In an effort to protect its reputation, the church issued its own statement to ABC, declaring that Remini's story is fabricated and that she is only after attention for herself and claimed that she was expelled from the church for her "ethical lapses."

Check out a clip from the interview:

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Leah Remini's full interview airs tonight at 10/9c on ABC. Her memoir, Troublemaker: Surviving Hollywood and Scientology, will be released onNov. 3.