Transcript for Leah Remini Calls Scientology an 'Extremist Religion'

We're going to begin with Leah remini and her very public break with scientology. The exclusive on "20/20" the other night brought interest on her book. You sat down with her over the weekend. She did not hold back. That's right. Leah told Dan Harris about her 30-ree relationship with scientology. A religion she and her sister were introduced do by their mother as children. After years of slowly questioning scientology, the beginning of the end happened at the star-studded wedding of Tom cruise to Katie Holmes. She was upset to find that a number of guests had filed what scientologists filed knowledge reports, complaining about her behavior before and at the wedding. Can you read me key lines? It starts with, I was displayed by the behavior of Leah remini. The behavior as a guest and friend was upsetting. I sat down with Leah remini for her reaction to all of it. The church of scientology has provided several statements to ABC news. I'm going the read part of the latest one. The full statement son to website. Oh, please go there and see that. Thank you for plugging. Her repeated ethical lapses and callous treatment of others led to a review, which resulted in her being expelled. What do you say to that? Um -- ah -- what do I say to that. Were you expelled? That's like saying, I broke up with you, you broke up with me. I don't know when that happened. I didn't get the memo that I was expelled. If that's what makes them feel good, I was there, like I said, for over three decades pip don't know when these lapses occurred. But again, not a thing endorsement of an organization who says they have thenses a to man kind and certainly, I was there skeeki seeking health. I don't know what else to say about that. Okay. You write a lot about Tom cruise. Mm-hmm. What is his role in the church? Well, that's unclear. Um -- but -- my experience, and there seems to be a lot of power there. That I couldn't subscribe to, as well, if I'm at dinner, we're going to dinner together, you're not going to write an internal church report on me that you thought I got a little -- you know, tipsy at your dinner party. And then, have to deal with that financially within your church. And be taken off of a spiritual path, so to speak, to deal with how you're interacting with this particular person. And so, the power seemed to be enormous. It was my experience. Were you, I mean, I can't imagine that. Being with someone in a social setting and being, were you afraid of what you said or didn't say or how you acted? Were you worried about getting written up? Constantly. That, again, there's policy in the church that requires parishioners to write each other up. I was guilty of this. What it does is it doesn't allow you to have the relationship with the person -- you have become a person who can't deal with your husband directly, your wife directly, your own child directly. And the church becomes your parent in that way. And then, my role is pushed out. Cruise's ex-wife Katie Holmes issued a statement we saw in Friday's special. She said, I regret having upset Leah in the past and wish her only the best in the future. You're smiling. Yes. I'm smiling because it almost makes me -- um -- want to cry. It makes me emotional because -- um -- at the time, that Katie and this particular crew were writing reports, it caused me a lot of time and pain and my family. Being reprogrammed. So, at the time, I was -- um -- fighting with her, I guess, for a lack of a better word, within the church. And now I know, really, what she was going through. Because at the time, I was thinking of myself. And my family and what we were going through. And although painful, I had no idea she was going probably through a lot more. Anding looking back now and seeing her and Suri, um -- out there in the world and her being able to be with her daughter, and live her life is -- you know, I'm touched by it. I'm touched by it. Because I know now she did what she did, leaving in the way that she did, because she had to protect her daughter, which, in a way, connects us now. And because -- Because part of what you did was to protect your daughter. Right. Because I didn't want my daughter to choose the church, ultimately, which is what I felt I would be raising was that. You choose your church. Which so many families do in these kind of extremist religions. I bet there's a lot you would like to say to Katie. Yes, yes. It's because we both left at the we're able to have this kind of grace towards each other. Because, we're back to being human.

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