>Gwen Le Berre doesn't understand the ''electrometer'' machine he keeps in his Normandy bedroom. He just knows it's a piece of kit from the Church of Scientology, which he blames for his mother's death.

Four days before Christmas 2006, Gwen's mother Gloria Lopez, a 47-year-old secretary, tidied her kitchen, hung out her washing, left her dull, suburban apartment overlooking the railway in Colombes, west of Paris, and walked the 30 metres on to the tracks. She stood with her arms outstretched, smiling at the driver of the oncoming commuter train. He couldn't stop in time.

After divorcing Pascal Le Berre, a French teacher, Lopez met Scientologists and signed up. The church was to become her life. Eventually, she moved to Paris, leaving her two children behind, to be nearer the Scientology Centre.

The Le Berres filed a legal complaint partly blaming Scientology for her death. In 10 years as a Scientologist, they estimate, Lopez spent up to $400,000 on courses and books - despite her secretary's salary of $3300 a month. Her family claims she was counselled by Scientology financial advisers and decided to sell a property she had inherited in Spain. ''They stole my mother,'' Gwen says. ''I don't feel I knew my mother apart from in her role as a Scientologist.''

Several investigations and legal cases in France have prompted Scientologists to complain of a ''climate of hatred'' and a state-sponsored ''inquisition'' against them. Together they have the potential to threaten Scientology's survival in France and undermine it elsewhere. Not only could its two flagship centres in France be closed down, but the church could be convicted of ''organised fraud''.