Katie Holmes was apparently concerned about Tom Cruise's relationship with Scientology Chairman of the Board, David Miscavige.

The 33-year-old pulled the plug on her five-year marriage to the Hollywood star last week after alleged concerns about Tom's involvement with the controversial church and the effect it could have on their six-year-old daughter Suri.

Britain's The Sun newspaper claims that David was best man at the former couple's lavish wedding in Italy and has been looming over their relationship ever since.

"Miscavige and Tim are joined at the hip. Tom runs every important decision in his life by him," an insider told the publication.

"Tom really values his opinion and Katie often felt like she came in second place. When it became clear how much influence he had over her husband she knew she had to get away."

Marty Rathbun, a former Scientology executive, said that Tom's ex-wife Nicole Kidman also had misgivings and turned "really sour on Scientology and kept pressing Tom to stay away."

"Her big issue was that Tom was becoming like Miscavige," Marty said. "Nicole didn't like the relationship that was developing between them."