Police detained three people close to France's richest woman on Thursday in an investigation into alleged tax evasion and money laundering, police sources said.

Francois-Marie Banier, a close friend of L'Oreal heiress Liliane Bettencourt whom she showered with gifts, Patrice de Maistre, her wealth manager, and Fabrice Goguel, her tax lawyer, were taken to the headquarters of the financial crimes division for questioning, the sources said.

The affair has embarrassed President Nicolas Sarkozy's government because of allegations by Bettencourt's former bookkeeper of illegal cash donations to conservative politicians.