Nanaterre, France: A French photographer accused of leeching a fortune off Liliane Bettencourt, Europe's richest woman, went on trial on Thursday in a case that has triggered a political scandal and shaken the government.

The hearing was swiftly adjourned to give police time to investigate secret recordings which raised concerns about Bettencourt's dealings with the state and turned a family feud into a political drama.

Francois-Marie Banier was charged with taking advantage of the "frailties" of 87-year-old Bettencourt, heiress of the L'Oreal cosmetics group, and persuading her to hand over gifts worth one billion euros ($1.74 billion).

The case was brought by Bettencourt's estranged daughter and both Banier and her mother have rejected her charges, insisting that the gifts were made in good faith.

Initially a bitter family dispute, the saga became politically explosive two weeks ago following accusations of a conflict of interest linking Bettencourt with one of President Nicolas Sarkozy's inner circle - Labour Minister Eric Woerth.

Secretly-recorded conversations between Bettencourt, whose fortune is estimated at 17 billion euros, and her advisers raised issues about the elderly tycoon's tax returns.

Woerth's wife worked until recently for a firm that helped to manage Bettencourt's fortune and opposition politicians have asked why the minister failed to launch a full tax review of the heiress despite concerns about her fiscal situation.

Woerth has angrily denied suggestions of malpractice and the case has become daily front page news in France, with an army of reporters at the opening of the trial on the outskirts of Paris.

Vengence

The family feud emerged in the opening stages of the trial, with Bettencourt's lawyer saying his client was victim of her only daughter's machinations.

"Liliane Bettencourt is at the center of a plot to humiliate her, to rob her of her dignity," said lawyer Georges Kiejman.

"(The daughter) wants to get the upper hand on her mother and vengeance on her mother."

If found guilty, Banier faces up to three years in prison and a 375,000-euro fine.

He would also have to return the gifts, including paintings and life insurance policies.

He sat in court doing sketches of the lawyers on a large artists' pad as his own attorney demanded proceedings be halted while police investigated the secret recordings of Bettencourt, that were made by her butler and handed over to the daughter.

"This trial is shameful. The methods that have been deployed have become sickening and impossible," said lawyer Herve Temime.

Whatever the outcome of the trial, the government is counting the cost of the collateral damage.

Bettencourt has long given donations to Sarkozy's UMP party and she met Woerth in his role as UMP treasurer at a time when he was also budget minister with oversight for the tax system.

Woerth moved to the labour ministry earlier this year, before the scandal broke, and his successor announced on Sunday that the authorities would review Bettencourt's taxes after one of her advisers said he had discovered an old Swiss bank account that had not been declared.

Earlier on Thursday, an opinion poll showed Sarkozy's approval rating had hit a record low, with political analysts saying the Woerth crisis had damaged his own standing.