Paris, Sep 22 (IANS): Liliane Bettencourt, the heiress to cosmetics firm L'Oreal, has died aged 94, her family has confirmed.

A statement said she had died at home "peacefully" overnight, BBC reported on Thursday.

With an estimated 2017 net worth of $40 billion, she was the world's richest woman.

She left the company's board in 2012 and was rarely seen in public afterwards, but remained in the news because of a high-profile exploitation case following her dementia diagnosis.

In a statement, the company's chairman and CEO Jean-Paul Agon said: "We all had a deep admiration for Liliane Bettencourt who has always watched over L'Oreal, the company and its employees, and who was very attached to its success and development.

"She personally contributed a lot to its success for very many years. A great woman of beauty has left us and we will never forget her."

Bettecnourt inherited L'Oreal group when her father died in 1957, Xinhua news agency reported.

She left L'Oreal board in 2012 after she had been declared unable to run her affairs, after a medical report showed she was suffering from dementia and Alzheimer's disease since 2006.

In 2011, her daughter Francoise Bettencourt Meyers awarded control of her mother's wealth or 33 per cent of stake in the French cosmetics empire, ending a a long family dispute over the fortune's management.