A Paris court is to rule Thursday in an appeal against a fine of hundreds of thousands of euros imposed on the Church of Scientology after it was found guilty of fleecing vulnerable followers.

A 2009 fraud conviction saw Scientology's Celebrity Centre and its bookshop in Paris, the two branches of its French operations, ordered to pay 600,000 euros ($790,000) in fines for preying financially on several followers in the 1990s.

The original ruling, while stopping short of banning the group from operating in France, dealt a blow to the movement best known for its Hollywood followers such as Tom Cruise and John Travolta.

Alain Rosenberg, the French leader of the movement, was handed a two-year suspended jail sentence and fined 30,000 euros on the same charge of fraud.

Five more Scientologists were given fines ranging from 1,000 to 20,000 euros for fraud or the illegal practice of pharmacy after plaintiffs said they were given vitamins and concoctions to improve their mental state.

On appeal, the prosecutor has sought a fine of not less than 1.5 million euros for the Celebrity Centre and the SEL bookshop, more than double the original penalty, and suspended prison sentences for most of the accused.

France regards Scientology as a cult, not a religion, and has prosecuted individual Scientologists before, but the original trial marked the first time the organisation as a whole had been convicted.

Church of Scientology lawyers in November raised five constitutional questions in a bid to get the trial annulled, but they were rejected, prompting the defendants and their lawyers to walk out.

The Celebrity Centre said in a statement on Tuesday that it had boycotted the trial because of "numerous violations of defence rights" and "doubts about the independence of the justice system felt throughout the trial, after the heavy interference of the executive in the judiciary."

Prosecutor Hughes Woirhaye said the Scientologists were adopting an "evasive strategy" and making "a deliberate choice of systematic denial".

Court hearings were curtailed because of the absence of the accused, while the four former followers who brought the case also withdrew from the trial.

The sole remaining witness was Catherine Picard, who heads Unadfi, an organisation that campaigns against sects and is a plaintiff in the case.

Picard testified to the "heavy debts, broken family ties" and the "state of subjection" that could result from the "sect-like methods" used by Scientology to "indoctrinate vulnerable people".

The original case followed a complaint by two women, one of whom said she was manipulated into handing over 20,000 euros in 1998 for Scientology products including an "electrometer" to measure mental energy.

A second claimed she was forced by her Scientologist employer to undergo testing and enrol in courses, also in 1998. When she refused she was fired.

Founded in 1954 by US science fiction writer L. Ron Hubbard, the Church of Scientology is recognised as a religion in the United States. It claims a worldwide membership of 12 million and 45,000 followers in France.