New York, USA - Tom Cruise has become the de-facto second-in-command of the Church of Scientology and is consulted on every aspect of the controversial group's planning and policy, according to a new book by the royal biographer Andrew Morton.
The writer paints a disturbing picture of the extent to the Hollywood star's life has been taken over by Scientology.
Morton claims that Cruise, 45, has long tailored his career and even his choice of romantic partners to furthering the organisation's ends.
In return, the "church", founded by the science fiction writer L Ron Hubbard, has come to rely so heavily on Cruise that he is now considered second in importance to its leader, David Miscavige.
Morton - who has written biographies of Diana, Princess of Wales, and the Beckhams - says that Mr Miscavige is so close to Cruise that he even joined him on his honeymoon in the Maldives after his marriage to Katie Holmes in 2006.
Scientologists pursued Cruise relentlessly as part of a campaign to recruit celebrities to an organisation struggling to be recognised as a religion.
When Cruise told Mr Miscavige that he had a fantasy of running through a wildflower meadow with his then newly wed wife, Nicole Kidman, the Scientology leader had staff plant a field full of wild flowers at the group's California base.
The star reportedly refutes each of the claims in the book, Tom Cruise: An Unauthorised Biography, which is being published in America on January 15.
Bert Fields, Cruise's lawyer and close friend, said Morton had conducted "no real independent research".
He told the Mail on Sunday: "[Cruise] has been told about it and naturally he knows there are a bunch of lies about him. It's a boring, poorly researched book by a man who never talked to anyone involved in Tom Cruise's life or anyone close to him."
Cruise was only 24 when he became a major Hollywood star with the pilot action film Top Gun. According to the book, Cruise first got involved in Scientology in 1986 when he was recruited by his first wife, the actress Mimi Rogers.
Scientology has been ridiculed over such beliefs as the doctrine that alien lifeforms called Thetans inhabit human bodies.
It has also been attacked over its practice of "disconnect" , in which members are encouraged to mix only with other Scientologists.