A former member of the Church of Scientology has said there is a form of "bullying and gangsterism" in the organisation.

It comes as a documentary on the group is set to air tonight.

The documentary was postponed from airing in the UK a few months ago, due to an outdated Northern Irish libel law.

Since this temporary ban, 'Going Clear' has gone on to receive seven Emmy nominations.

And after legal concerns were alleviated, the documentary will air tonight.

Former member Pete Griffiths joined the Church of Scientology after his brother and ex-wife got involved in it.

"I knew it was a cult, I'd been told all these things - however when you don't see harm coming to people that you know and love, your fears are allayed somewhat" he told Newstalk Breakfast.

"My job was to get people in, so I had to do these stress tests and the personality tests and then try and sell people something".

"The aim is to make you feel so bad, that you will buy what they have to offer".

He says their belief is that man is an immortal being that has had his "God-like powers" wane over the years - but you can get these back "if you pay".

"Every course costs a certain amount of money...eventually it starts getting into the hundreds and then the thousands - and the upper-level courses do cost thousands".

He says once you become Scientology staff, you can work 17 hour days for nothing.

"We went for weeks without pay - it's unheard of - but you do it because you think you're doing it for the greater good of mankind".

On tonight's documentary, he says: "You can expect to meet a lot of ex-members who are simply sat there, telling the truth about their own experiences".

"I think the big question is how can these people be allowed to continue to get away with this".

Listen to his full interview below:

The Church of Scientology has rejected the claims made in Going Clear, saying "free speech is not a free pass to broadcast or publish false information." The Church insists Gibney's production is not truthful or accurate in its depiction of the religion.

The Church of Scientology has said:

"The Church of Scientology responded vehemently to the film, complaining to film critics about their reviews and denouncing the filmmakers and their interviewees."

'Going Clear' airs tonight at 9pm on Sky Atlantic