Billionaire businessman Kerry Packer secretly investigated his son James' links to the Church of Scientology in the months before his death.
The Daily Telegraph can reveal that the late Mr Packer arranged a private meeting with a high-ranking Australian religious official in mid-2005.
Scientology and the basis of the cult-like Hollywood religion dominated the discussions.
The media mogul died on Boxing Day that year, handing full control of his $7 billion empire to James.
"He was worried about Scientology - I don't think he believed in it at all," a source with intimate knowledge of the meeting said.
"He was wanting to know whether it was sound and what it was all about."
Close friend and prominent Scientologist Tom Cruise was among hundreds of high-profile guests at James' lavish wedding to model Erica Baxter on the French Riviera yesterday.
James was introduced to Scientology by Cruise during the actor's ill-fated marriage to Nicole Kidman in the late 1990s.
James is believed to have found spiritual solace in the movement after the $1 billion One.Tel collapse in 2001 and in the wake of his split from wife Jodhi Meares 13 months later.
James has never spoken publicly about his association with the organisation but has regularly attended sessions at its Sydney headquarters.
Ms Baxter also has flirted with the faith, which has forged a stronghold in Hollywood, where it boasts many high-profile followers including Cruise, John Travolta, Kirstie Alley, Priscilla Presley, Lisa-Marie Presley and Mimi Rogers.