Scientology has always been keen to recruit celebrities to its side. L Ron Hubbard launched Project Celebrity in 1955 with that aim and the church stresses his - and its - commitment to artists. "A culture is only as great as its dreams and its dreams are dreamed by artists," Hubbard once wrote. Of course the publicity garnered by a celebrity endorsement doesn't do any harm either.

Tom Cruise and John Travolta are the most famous celebrities to have embraced Scientology. Cruise discovered the church when he was married to Scientologist Mimi Rogers between 1987 and 1990 and has become an outspoken champion of it. He has also adopted Scientology's anti-psychiatry stance.

Travolta, meanwhile, credits the church with "putting me in the big time". Quoted on the Scientology website, Travolta says: "I have a wonderful child and a great marriage because I apply L Ron Hubbard's technology to this area of my life. As a Scientologist, I have the technology to handle life's problems and I have used this to help others in life as well."

Other famous Scientologists include the singers Beck and Isaac Hayes, jazz musician Chick Corea, and the actors Kirstie Alley, Erika Christensen, Juliette Lewis, Priscilla Presley and Anne Archer. Beck and Christensen were both raised in Scientology families, with Christensen attending the Delphi Academy in Los Angeles, which uses the Applied Scholastics method of teaching. Beck's wife is also a second generation Scientologist.

To cater for its growing list of celebrity converts, the church has built so-called celebrity centres on two continents. These buildings are open to the public but intended mostly to service "politicians, leaders of industry, sports figures and anyone with the power and vision to create a better world", according to the Celebrity Centre International website.

The first celebrity centre was established in Los Angeles in 1969. Today it can be found at Franklin Avenue, Hollywood, a palatial building whose lobby looks more like a five star hotel than a house of religion.

There are now also celebrity centres in Las Vegas, Dallas, Portland, Nashville and New York. In Europe there are celebrity centres in Vienna, Dusseldorf, Paris, Florence and London. The Church of Scientology even has a magazine called Celebrity. Launched in 1972, it claimed a circulation of 97,000 by the late 1990s. It contains articles on celebrity Scientologists as well as what are known as completion lists, which show the courses that have been taken by the celebrity centre members.