Kirstie Alley claims Scientology saved her life.
The 'Look Who's Talking' star appears in a promotional video called 'Orientation: A Scientology Information Film', where she gives her own reasons for following the bizarre sci-fi cult.
Alley, 57, said: "Honest to God truth, without Scientology, I would be dead. Personally, I recommend it."
The leaked video comes after a series of video clips emerged on the internet featuring 'Mission: Impossible' star Tom Cruise.
In one of the clips the 45-year-old actor - a devout follower of the religion - claims Scientologists "are the authorities".
He said: "A Scientologist is somebody who can look at the world and really see it for what it is. And not just see it but be able to go 'pow' and actually do something about it. And be somebody who is not asking permission to do that. Why ask permission? We are the authorities."
In another clip - taken from footage recorded after Cruise collected the Freedom Medal of Valor from the religion's leader David Miscavige - the star claims only Scientologists can help in road accidents.
He said: "Being a Scientologist, when you drive past an accident, it's not like anyone else you drive past. You know you have to do something about it because you know you're the only one who can really help."
Cruise also insists Scientology can save drug addicts, rehabilitate criminals and bring about world peace.
Tom Cruise is the World's Best Scientologist - Looks at His Passion! (LINK)