PARIS

Ten people have gone on trial in France on charges surrounding their alleged exploitation of France's richest woman -- frail 92-year-old billionaire L'Oreal heiress, Liliane Bettencourt.

A court in Bordeaux began hearing the case Monday in an expected five-week trial which has transfixed much of France with a drama involving high-profile and rich names surrounding what is believed to be the world's 12th largest fortune. 

The ex-campaign treasurer to former French President Nicolas Sarkozy, Eric Woerth, socialite artist and photographer Francois-Marie Banier and some of Bettencourt's former lawyers and advisers are among the defendants, some of whom face up to five years imprisonment and a fine of €375,000 ($420,000) fine if convicted of charges of abusing the declining mental health of the billionaire, breach of trust and money laundering. 

The case comes after Bettencourt’s daughter, Francoise, questioned in 2007 the amount of money her mother, who is suffering from dementia, was giving to her close friend Banier.

The artist received more than €400 million worth of gifts including paintings by Picasso and Matisse and millions of euros in cash from Bettencourt, whose wealth has been estimated by Forbes magazine at €33 billion, after he became a close friend and confidant.

'Cash in envelopes'

Banier at one point was named as the sole heir to Bettencourt's fortune, in a decision which was later overturned.

Patrice de Maistre, who was in charge of managing Bettencourt’s vast fortune, is also accused of misappropriating several million euros and encouraging her to commit tax evasion.

He also faces charges related to claims he persuaded Bettencourt to hand over envelopes of cash to members of the then-ruling UMP, including his friend Eric Woerth, who was campaign treasurer for Sarkozy during his 2007 run for the presidency.

The scandal damaged Sarkozy's presidency and he went on to lose the 2012 presidential election and was placed under formal investigation for illegal campaign financing and taking advantage of Bettencourt.

The charges were dropped in October 2013, after which Sarkozy launched a political comeback which led to him winning the leadership of the right-wing UMP late last year.

Nazi accusations

Bettencourt’s vast fortune along with the control of cosmetics giant L'Oreal were both placed under the guardianship of her family after she was declared in 2011 to be unfit to run her own affairs after a medical report showed she suffered from "mixed dementia" and "moderately severe" Alzheimer's disease.

Her father Eugene Schueller founded the firm in 1909, growing it from a hair-dyeing business into a world-leader.

Liliane, whose mother died when she was five, began work with L'Oreal at the age of 15.

Accusations that Eugene and Liliane's husband, Andre, collaborated with the Nazis during World War II have long dogged the Bettencourt family.

*Additional reporting by Hajer M'tiri in Paris