Transcript for Ron Miscavige on Life at Scientology's 'Gold' Base: Part 3
Reporter: Two hours east of Los Angeles, in Hemet, California, sits a 500-acre scientology compound known as gold base. The church characterizes the base as a slice of scientology utopia. These official videos show a spotless complex with state-of-the-art facilities, gorgeous landscaping and flowing fountains. They tell us the food is great too. When she arrives for her interview with "20/20," scientology attorney Monique Yingling brings along these baked goods as edible proof. If you talk to the staff, they'll tell you it's a worker's paradise. It couldn't be a better place to work. Reporter: This is where Ron miscavige works after signing up for the sea org in 1985. At first, Ron says he enjoys himself. He joins the band and gets to play all over the world. That's him jamming with scientologist and soul legend, Issac Hayes. What's more, he believes he's helping to change the world through scientology. On a more personal note, he meets his second, and much younger, wife, Becky Bigelow. So Ron is happy, for a time. But he says he can't help but notice his son's sharp-edged new management style. David was backstage literally tearing me apart verbally for 55 minutes. Cursing, yelling, screaming at me. Reporter: One night at a church event in the late '80s where Ron is performing, he says David gives him an extended tongue lashing, with other people looking on. When he's screaming at you, do you ever think I changed this guy's diapers? No kidding. Of course I did. Of course I did. And that isn't the only time it happened. Look, I'm the one that got him in scientology. I raised him. Good or bad. And to come to this, what the hell is this? This is nuts. Reporter: The church insists Ron doesn't actually know much about David's management style because they simply didn't spend much time together. David was busy with much bigger things, like conducting this live interview on ABC's "Nightline" with Ted Koppel in 1992. You want to bring me up an allegation, you confront me with it. Reporter: And of course there were the celebrity scientologists to manage, like "King of queens" actress Leah remini, now a vocal ex-member who published her own memoir about her life in the church, "Troublemaker," last year. I think, uh, David miscavige loves his position and power and uses that power to hurt people and comes down hard on anybody who questions him. Reporter: Leah was a big deal, but there is no more prominent celebrity scientologist than Tom cruise, with whom David bonds in 1990 during the filming of "Days of thunder." What's the relationship between your son and Tom cruise? Tom cruise thinks that David is the top thetan or top spiritual being on this planet. Reporter: The top spiritual being on this planet. Yes. Now that L. Ron Hubbard is gone, they're like the best of buddies. Reporter: What is the difference between being a sea org member, and being a celebrity in the church? Well, it's like, you know, getting to be at the cool table. Reporter: For those not at the cool table, life at gold base can allegedly be more harsh than these glossy church videos might suggest. By 2006, Ron and Becky move onto the base, as most staff members are told to do, and soon, he says, they start chafing at some serious restrictions. I'm living on a compound where your mail going out is read before it's sealed and sent out. Where before you get your mail, it's opened and read before you get it. Reporter: And your phone calls? Phone calls, you're on the phone, somebody else is listening on an extension. I was in charge of the security in all aspects for every acre of property here. Reporter: When "20/20" visits gold, we bring along Gary Morehead, a former scientologist turned critic who says he was once director of security for the church. I would go through people's personal belongings out of their berthing, where they slept, obtaining bank records, date of birth, passwords, any personal information, where their family addresses were. Reporter: Former scientologist mark fisher says when he tried to leave the church in 1990, his onetime roommate, David miscavige, exploded. He was kicking, pulling at me, pulled my hair, punching at me. I have no idea how long it went on. It finally stopped. And then I reached behind my head because it felt kind of moist, and I pulled my hand back and my hand was bloody. And I said, "You -- you made my head bleed." Reporter: We spoke to a man named mark fisher, who claims that in the summer of 1990, David attacked him. To your knowledge, is any of this true? Not that I know of. Reporter: But we have heard from numerous former staff members that David miscavige has at times punched, kicked and even choked scientologists. To my knowledge that is not true. Reporter: Why do you think they're saying this? Because I think they believe it is a way to somehow get at David miscavige. He is so caring. Reporter: The church sent us 126 interviews they recorded with their parishioners praising their leader. He has the heart of a lion. Dedicated to our religion. Mr. Miscavige is an amazing person. I will love him forever. Reporter: Ron's testimony is different. He says by the late 2000s, the crushing workload, the discipline and lack of sleep on the base becomes unbearable. The church rejects those claims, telling us long and hard hours and a restrictive lifestyle are part of the mission sea org members sign on for in those billion-year contracts. They're very proud of what they do and they may work hard, they may work really long hours, even longer than we do, but they enjoy it. Reporter: As for Ron -- He was working with first class musicians in one of the best studios in the world. He had nothing to complain about. Reporter: To prove it, the church has provided "20/20" with pictures of Ron at leisure, enjoying fancy birthday meals provided by his son and even getting a car for his birthday from David and his two daughters. My name is peter schless, I'm a songwriter. Reporter: The church also sent us video testimonials from Ron's former bandmates. Ron was an embarrassment to me, personally. Reporter: And letters in which those band members call Ron lazy, saying he used racial and ethnic slurs, was a poor musician and a disgusting pig. Do you know of any other church that criticizes former members in the way in which scientology does? Well, I -- I think it all depends on the circumstances. Certainly I -- you see that happen with respect to the Vatican and so on when the Vatican gets attacked. I mean, they have something to say about the attackers. Reporter: If somebody leaves the catholic church, do you really think they're going to be on the receiving end of this level of vitriol? Because people leave and criticize the catholic church all the time. Yes, exactly. And I do think that if people in the church are asked for their opinion of this particular person, that you may well get the same kind of criticism. Reporter: But it's not as if the people were just randomly asked. This is the church itself asking its parishioners, videotaping it and giving it to ABC news. Well, again, the facts are what they are. Reporter: Ron points to this video, saying if he was as bad as his former colleagues now say, why then was he allowed to play at this birthday party the church threw for Tom cruise aboard its luxury ship, the freewinds? There's David and Tom rocking out while Ron performs. That looks like fun, but Ron also remembers a much less pleasant aquatic experience. He says he was subjected to a practice called overboarding, a disciplinary measure in which a sea org member in trouble is thrown into the water, clothes on. It can be done with respect to one individual, if there's you know, some sort of ecclesiastical discipline thing or it can be done as a group. Reporter: The church says overboarding is voluntary. Ron disagrees. I'm going out there and I'm thinking to myself, this is straight lunatic asylum stuff. This is going to make me better? The only effect it had on me is make me all the more want to possibly get out of there. Reporter: And that's exactly what Ron and Becky decide to do.
This transcript has been automatically generated and may not be 100% accurate.