The Church of Scientology and six of its French leaders went on trial on Monday on charges of organised fraud that could lead to an outright ban on the organisation in France.
The court is hearing a complaint from two women, one of whom alleges she was manipulated into handing over 20,000 euros (28,000 US dollars) for costly Scientology products, such as an "electrometer" to measure mental energy.
She says she was approached in a Paris street by a Scientologist in late 1998 who offered a free personality test, at a time when she was feeling psychologically fragile.
After being told that her test results were poor, the woman was sold a series of "life-improvement courses", vitamins and other products that she could ill afford, landing her in debt.
The second complainant alleges she was forced by her Scientologist employer to undergo testing and enroll in courses in 1998. When she resisted, she was fired.