Six months after the death of his son, John Travolta is thinking of quitting Scientology, friends say. The actor has become a recluse since the boy died suddenly while the family was on holiday in The Bahamas.

A neighbor of Travolta said: "We used to see him driving around on a buggy with his son. Now it's just John by himself."

Travolta is reportedly now furious at the Church of Scientology's treatment for Jett's autism. Scientology sees autism as psychosomatic and proscribes treatment with vitamins and detoxification - not prescription drugs.

Travolta has reportedly made private threats to leave the church. Rick Ross, an author and Scientology watcher of 30 years, said this was a dangerous move for a high-profile practitioner. "Scientology keeps files on its celebrity members containing embarrassing personal information about them. And Scientology has proven in the past that it has a penchant for releasing that information to embarrass people who have left and who have said things it doesn't like."

Travolta's wife, actress Kelly Preston, campaigns against psychiatric drugs. Jett was taken off the antiseizure-drug Depakote, the family's lawyers have confirmed. Preston is said to have enrolled the boy in a Purification Rundown course offered by the religion.