June 14 - Doctors say a brain disease has made L'Oreal heiress Liliane Bettencourt unable to run her affairs and she must be placed under enhanced legal guardianship, a source close to the affair said on Tuesday.

French L'Oreal heiress Liliane Bettencourt has a fortune worth an estimated $21.7 billion (Photo:AFP, Francois Guillot)

The claim came as the battle heated up between the 89-year-old billionaire and her daughter Francoise Bettencourt-Meyers, who has taken legal action alleging that her mother is prey to hangers-on who want to defraud her.

The source, who asked not to be named, disclosed to AFP an analysis of the 89-year-old billionaire's health by court-appointed doctors who said a "brain disease" had caused an "alteration of the mental and physical faculties."

Bettencourt, France's richest woman, "must be given a measure of protection in carrying out her civil life, regarding her patrimony and personal affairs, in the form an enhanced legal guardianship," this medical report said.

The three doctors submitted their report last month based on Bettencourt's medical records but did not examine her personally, the source said. Le Monde newspaper also reported their recommendations.

Entangled in political scandals, the feud between Bettencourt, heir to the L'Oreal cosmetics empire whose fortune is estimated at around 15 billion euros (21.7 billion dollars), and her daughter broke out afresh last week.

Her daughter took legal action against Bettencourt's lawyer Pascal Wilhelm, alleging he had a conflict of interest in managing her affairs.

Bettencourt-Meyers sued a friend of her mother last year for abuse of trust, but the trial broke down in a web of allegations implicating President Nicolas Sarkozy's government in claims of illegal political funding.

Wilhelm declined to comment to AFP on the details of Tuesday's claims but denounced what he called "a clear violation of medical confidentiality."

The type of "enhanced legal guardianship" recommended by the doctors would allow the appointed guardian to oversee Bettencourt's spending but falls short of granting the guardian the status of a full legal trustee.