The past few days have not gone well for the secretive religion known for its celebrity followers

Most religious organisations can weather a high-profile defection or two. Many might successfully explain away a fraud conviction in a foreign criminal court, or deal with the spectacular suicide of a member, or muddle through a less than stellar public performance by a prominent spokesman.

Rarely, though, does a religion have to face up to all these challenges in the same week.

The past few days have been little short of a nightmare for Scientology, the strange, secretive religion that thrives on its coterie of Hollywood celebrities and its promises of personal empowerment through psychological counselling.

First came the defection of Paul Haggis, the Oscar-winning screenwriter and director of such hits as Crash, Million Dollar Baby and In the Valley of Elah, who accused the church fathers of lying about everything from their position on gay marriage to their policy of ordering certain followers to sever their ties with close family members.

Haggis said he knew for a fact that Scientology practices a policy of "disconnection" – something it denied in a recent interview with the cable news channel CNN – because his own wife was ordered to stop talking to her parents for more than a year.

"To see you lie so easily, I am afraid I had to ask myself: 'What else are you lying about?' " Haggis wrote in a long resignation letter to church spokesman Tommy Davis, which was meant to be confidential but found its way onto the internet over the weekend.

Davis himself, meanwhile, earned less than positive notices for his decision to walk out of an on-air interview with the British television journalist Martin Bashir. Bashir invoked both the science-fiction origins of Scientology and what are widely believed to be its deepest secrets when he asked: "Do you believe that an intergalactic emperor called Xenu brought his people to earth 75m years ago and buried them in volcanoes?"

Davis called the question offensive, said it was against his religion even to talk about the subject, pulled off his mike and walked away.

Meanwhile, a French court found the church guilty of fraud because of the large amounts of money it charges its members to conduct idiosyncratic counselling sessions (known as "auditing") and other services. The court, essentially characterising the whole enterprise as a scam, imposed a fine of €600,000.

And on the other side of the world in Brisbane, Australian investigators openly criticised the church for failing to hand over documentation they want to examine for clues about the suicide of a 30-year-old soldier who threw himself at an electricity substation tower two years ago. A coroner's report said church officials had been pressing the soldier, Edward McBride, to finish the final stage of his auditing and called him 19 times in the 48 hours before he took his life.

Davis, the church's 37-year-old spokesman, has spent much of the past week issuing denials and rebuttals. He insisted the church never supported an anti-gay marriage initiative in California and that the San Diego chapter's inclusion in a list of supporters was a mistake. He told one interviewer his remarks about "disconnection" on CNN had been misunderstood.

He also faced questions about John Travolta, the Hollywood leading man and hitherto loyal Scientologist who recently acknowledged that his dead teenage son Jett suffered from autism - a condition Scientology does not acknowledge along with other mental illnesses (Scientologists believe that psychiatry is a fraudulent "industry of death").

While Jett was still alive, Travolta and his wife Kelly Preston insisted he suffered instead from Kawasaki disease, a condition characterised by inflamed arteries.

Davis also came under scrutiny for his own activities – including the allegation that he once so displeased the church that he was made to scrub toilets with a toothbrush for a week (he denies it ever happened).

Davis is the son of the Hollywood actress Anne Archer, another prominent Scientologist, and is believed to owe his rapid rise through the organisation as personal minder to the biggest star adherent of them all, Tom Cruise.

Many of the church's misadventures this week can be traced back to two huge recent defections.

Mike Rinder and Marty Rathbun have been described as Scientology's equivalent of the top Nixon aides HR Haldeman and John Ehrlichman in the Watergate scandal. Together, they helped the St Petersburg Times newspaper in Florida put together a huge three-part series last June in which they and other defectors accused church leader David Miscavige of using physical and psychological violence to keep his supporters in check.

They said Miscavige would repeatedly slap and kick his subordinates, and encourage them to do likewise. He would also force his fellow church members to jump fully clothed into pools or lakes, and play all-night games of musical chairs.

The church said at the time the accusations were baseless and motivated by the defectors' desire to stage a coup and take over the church for themselves. The defectors said they had no such interest and merely wished to expose the dark side of the religion to which they devoted most of their lives.