Ex-Scientologist Marc Headley, who says he worked closely with Miscavige for 15 years during his long tenure with the church, calls his relationship with Tom Cruise "the most intense, expensive bromance in history."

'If He Dies, He Dies' will offer a rare inside look at the church and its leader.

Ronald Miscavige Sr., the father of Scientology leader David Miscavige, has signed a deal to write his memoir, If He Dies, He Dies, with St. Martin’s Press, the publisher confirmed to The Hollywood Reporter.

The title refers to a story in an April 8 Los Angeles Times article that revealed that David Miscavige had put his father under surveillance because he had grown estranged from the church and his son. When one investigator saw Ron grab his chest in an apparent heart attack, he called his Scientology employers to see if he should intervene. David personally called him back and said, “If he dies, he dies.”

[The Church of Scientology disputes the investigator's account: "Mr. Miscavige has always taken care of his father and continues to do so,” wrote Church spokesperson Karin Pouw in a statement to THR. "Beyond that, as a matter of policy, neither the Church nor Mr. Miscavige comments on members of his family.” See full statement below.]

Longtime Scientology observer Tony Ortega reported the news of the book on his blog about the church, The Underground Bunker. Publisher's Marketplace, a site followed by publishing insiders, also reported news of the book.

David Miscavige, 55, has been the head of the controversial religion since soon after founder L. Ron Hubbard died in 1986. He was introduced to the church by his father, who joined in the late 1960s.

David Miscavige has been known for his extravagant lifestyle and efforts to cultivate Hollywood stars as church members. A true insider account of life in the church and a full portrait of its leader by his father would be a blockbuster book. David’s niece, Jenna Miscavige, wrote an unflattering account of her uncle in 2013’s Beyond Belief: My Secret Life Inside Scientology and My Harrowing Escape.

The church has come under fire lately, with director Alex Gibney suggesting it should lose its tax exempt status. Gibney directed Going Clear, a documentary for HBO critical of the church based on the best-selling book of the same name by Lawrence Wright.

The Miscavige Sr. is said to have been working on the book for a number of years. No publication date has been announced.

The Church of Scientology statement to THR:

Mr. Miscavige has always taken care of his father and continues to do so. Beyond that, as a matter of policy, neither the Church nor Mr. Miscavige comments on members of his family. The Church knows nothing beyond media reports about any purported book.

As for the purported emergency incident involving an investigator and the second-hand account of an alleged conversation containing a despicably false quote, Mr. Miscavige's attorney, Michael Lee Hertzberg, is on record stating that Mr. Miscavige does not know the investigator, has never heard of the investigator, has never met the investigator, has never spoken to the investigator, never hired the investigator and never directed any investigations by him.

So let me be clear: No such conversation with Mr. Miscavige ever took place and any claim that one did is provable bullshit.

July 1, 1:10 PM: updated to include a statement from the Church of Scientology disputing the title quote.