Mother and daughter are said not to be on speaking terms
The daughter of Europe's richest woman, a L'Oreal heiress, has asked that she be placed under judicial supervision to stop her handing away her money.
Francoise Bettencourt-Meyers argues 87-year-old Liliane Bettencourt is no longer in her right mind after she gave away 1bn euros (£910m) to a friend.
Proceedings have been launched in a Paris court to have Mrs Bettencourt placed under court authority.
But Mrs Bettencourt has dismissed claims she was conned by a fraudster.
She has insisted she was in full possession of her faculties when she gave money and gifts to 62-year-old photographer Francois-Marie Banier over a several-year period.
Olivier Metzner, acting for Ms Bettencourt-Meyers, 56, said she was seeking "only to protect Liliane Bettencourt" from exploitation by the unscrupulous.
A lawyer for Mrs Bettencourt rejected this, accusing the daughter of trying to take control of her mother's finances. The two are reportedly not on speaking terms.
Rated by Forbes as the world's 21st richest person, Mrs Bettencourt has an estimated fortune of 13bn euros, largely due to her 30%-stake in the global cosmetics giant L'Oreal.
Mrs Bettencourt-Meyers has pressed criminal charges against Mr Banier, accusing him of extorting vast sums of money from her malleable mother, in a case that is due to come to court next week.
"We have already taken action against the predator," said Mr Metzner. "Now we are taking action to protect my client's mother, to show that she is nothing more than a victim."
Mr Banier has refused to make any comment on the case.
Mrs Bettencourt, in an interview a year ago, angrily denied her longtime friend Mr Banier had taken advantage of her, saying: "My daughter has to realise that I am a free woman."