Australia - Figures released to Lateline from the Australian Census show that in 2011, just 2,163 Australians called themselves Scientologists, a decrease of 13.7 per cent from the 2006 Census.
In 2009, Scientology spokesman Tommy Davis told ABC's Four Corners program there were "tens, if not hundreds of thousands" of Scientologists in Australia.
The Church of Scientology would not grant an interview to Lateline, but in a statement said: "The Census figures are not an accurate reflection of the growing number of people visiting our churches and actively participating in Scientology both in Australia and internationally."
Paul Schofield, who was a member of the Church for 29 years, before leaving in 2008, says Scientology has a history of fudging their figures.
"Scientology is totally obsessed with statistics. If your statistics are not going up you get punished, and they are probably the world’s most creative people with numbers when it comes to increases.
Jedis on the up
While Scientology is going backwards, other minor religions have registered increases.
The number of Pantheists went up by 35 per cent, while the Rastafarian movement increased by 30 per cent.
Australians who describe themselves as Jedis, now number over 65,000, over 30 times higher than Scientology's figures.
Wiccans, who dabble in witchcraft, have topped 8,000.
The release of the Census figures follows more bad news for the Church of Scientology.
Wendy Honnor, one of the most prominent Scientologists in Australia, has quit the church.
In an email to friends Ms Honnor wrote, "The only way out is out. I am free."
Ms Honnor is a previous winner of the International Association of Scientologists' Freedom Medal.
The Freedom Medal is considered the highest honour a Scientologist can achieve and has previously been awarded to Tom Cruise.
Wendy Honnor is thought to be the only winner of the Freedom Medal to quit and publicly distance herself from the church.
In her email Ms Honnor wrote: "I agree with all the points raised in the New Year 2012 email of Debbie Cook."
Debbie Cook is a former church official in the United States who was critical of the corporate culture of Scientology and the church's leader David Miscavige.
In a statement, the Church of Scientology said "Religion is a matter of personal choice and Ms Honnor has always made her own decisions in her life."