AN AUSTRALIAN man who was a former high-ranking member of the Church of Scientology is calling for the religion to be "totally dismantled" because of the human rights abuses he says it inflicts on its followers.

David Graham has gone public after years of keeping quiet when he feared retribution from the church.

He says members are encouraged to cut ties with non-Scientologists. And they are threatened with being ostracised from members, including family and friends, if they try to leave the church - an act known as "disconnection".