The prospect of sending six-year-old Suri to the Sea Organisation, or Sea Org as it is known, is what is said to have been the final straw for Katie Holmes before she filed for divorce.
The clergy like group is run like a military clique from the Scientology Gold Base in California which has a sniper-style nest bunker on the site.
All aboard: The masts of a ship-like structure next to a swimming pool at the isolated Gold Base compound in the Californian wilderness
Headquarters: The Scientology base in California has a church, mansion, golf course accommodation and swimming pool
Members are banned from having children, are paid just $50 a week and can be punished for simply looking at somebody the wrong way by being thrown in ‘The Hole’ - two trailers set aside for punishment.
It has been investigated by FBI agents looking into human trafficking and one member claimed he was locked in a ship’s hold for 18 hours a day with no food.
Holmes is also said to have been alarmed at her daughter being pushed into an academy partly paid for by Will Smith which acts as a feeder to a school popular with Scientologists.
And according to interviews with former Scientologists and former Sea Org members, her fears appear to be well founded.
Sea Org is the Scientologist equivalent of a religious order and is thought to be around 6,000 strong.
In recent years ex-members including Oscar-winning director Paul Haggis have spoken out about the brutal regime which operates inside.
The one billion year pledge is supposedly to ‘symbolise their eternal commitment to the religion' but is made by children as young as 10, something Haggis likened to the treatment of ‘child slaves in Haiti’, he has told the New Yorker.
Members are paid just $50 a week and banned from leaving their base or they are tracked down by a special team who use emotional pressure or physical force to make them come back.
Spiritual home: The $9.4million mansion which former members claim was built for the return of L. Ron Hubbard who died in 1986
Keeping watch: The Gold Base compound has razor-tipped fences, motion sensors and what appears to be a heavily camouflaged sniper-style nest bunker that over looks the entire property (pictured)
Devout: The religious technology center at the gated compound which sits in arid foothills, 90 miles from LA
Former Scientology security chief Gary Morehead has claimed that he tracked down more than 100 Sea Org members who left in his 13 years on the job using what he called a ‘blow drill’, referring to the techniques he employed to hunt people down.
If Sea Org members try to leave they are also given a ‘freeloader tab’ which is a bill for all the work they have received, and can run into six figures.
Under the influence of Scientology ‘elders’, Sea Org members are convinced to ‘volunteer’ for punishments which can include being given poor quality food, sleep deprivation or being banned from talking to anyone, ABC news has reported.
They can also involve manual labour, wearing black clothes to mark you out from everybody else - and can go on for years.
Then there are the alleged beatings at the hands of leaders and The Hole, two trailers which can hold up to 100 people forced to do group confessions all night.
In one episode detailed in an piece in the New Yorker, those put in The Hole were told that they had to play a game of musical chairs and only the person who won would be allowed to stay.
As the Queen hit ‘Bohemian Rhapsody’ boomed out of the stereo, it took until 4am before there was a winner, by which time things turned violent with one chair being ripped in two.
Battle: Katie Holmes has filed for divorce from husband Tom Cruise and has asked for sole custody of daughter Suri. The actress reportedly dislikes and distrusts Scientology to which her husband is devoted
Faithful: An aerial shot shows members at Scientology HQ Gold Base - where it has been claimed that members are paid just $50 a week and tracked down if they try to leave
Sea Org has also been dragged through the courts and in 1985 former member Lawrence Wollersheim sued for $25million after claiming he had been kept for 18 hours a day in a ship’s hold.
Left in the hold with no food and unable to sleep, he alleged that he suffered ‘emotional injury’ as a result of his ordeal.
He was awarded $30million though this was reduced to $2.5million on appeal.
In 2009 former Sea Org members Claire and Marc Headley sued the church after joining in their teens and falling in love.
She claimed to have been pressured into having two abortions because rules state she could not have children, although they lost the case.
Sea Org dates back to 1966 when Scientology founder L Ron Hubbard sought to take his followers on sea breaks to continue his research into the ‘upper levels of spiritual awareness’.
He bought several small ships and staffed them with a young crew of Scientologists and reportedly went looking for treasure he had hidden in a previous life.
Rough terrain: Members are allegedly banned from leaving the isolated base, according to former members
Fun and games? Leisure facilities on the compound include basketball courts
Former Sea Org member Janis Grady has claimed that she was once on a boat with Hubbard who showed her a map with crosses on it and claimed there was buried treasure under each cross.
Sea Org is run out of Gold Base, which is the Scientology HQ located 90 miles east of Los Angeles in Gilman Hot Springs, California.
The 500-acre compound has a film studio called Golden Era Productions on which Cruise supposedly does some of his work.
The security measures are extreme and include motion sensors, razor tipped wire and what appears to be a camouflaged nest bunker with clear sightlines over the entire property.
There is also a golf course, accommodation blocks, education buildings and the $9.4million mansion which former members claim was built for the return of Hubbard, who died in 1986.
The school which supposedly alarmed Holmes was the New Village Leadership Academy in Calabasas, California, which has received a $1.2million from Smith as a donation..
Feeling green: The compound has a number of leisure facilities including swimming pool and golf course for members
Devotion: The church at the Scientology compound in California
His wife Jada Pinkett-Smith has denied it is a Scientology school and said that it would be ‘straight evil’ to suggest she was putting money into a education establishment which also sought to convert children to any religion.
Donation: Will Smith, with wife Jada, gave $1.2million to the New Village Leadership Academy
But while it is secular, multiple reports across media organisations in the US and the UK claim it does have ties to Scientology and uses ‘study technology’, which was created by Hubbard.
It also feeds into the $42,000 a year Delphian School in Oregon where as many as half the pupils are Scientologists, the Independent reported.
Among the pupils there are Connor and Isabella Cruise, 17 and 19, Cruise’s children with ex-wife Nicole Kidman.
Marty Rathbun, a former senior executive in Scientology told the Independent: ‘Suri is coming to an age where she gets educated enough to get locked into the faith.
‘That's why there's almost certainly truth in the consideration that schools have started coming into play in all this.’
Since announcing her divorce, Holmes has reportedly enrolled Suri in a Catholic school in New York.
Scientology spokesmen have denied the claims in the New Yorker article.
The organisation has also claimed that Suri is too young to join Sea Org, even though Cruise is its most high profile member.
Wilderness: Sea Org is run from Gold Base in Gilman Hot Springs, Colorado
The road less traveled: The strict community of Scientologists have installed tight security at the base