The French authorities have triggered a probe into alleged involvement of L'Oreal cosmetics heiress Liliane Bettencourt in a million-dollar scandal.

The police investigated the house of her daughter Francoise Bettencourt-Meyers on Wednesday in upmarket Paris suburb of Neuilly.

A number of separate investigations are being pursued for determining the alleged tax evasion and illegitimate funding of President Nicolas Sarkozy's campaign by Liliane Bettencourt.

Bettencourt-Meyers have alleged that her mother is not in a good mental condition. She also said that the 87-year-old lady has been involved in the money laundering cases.

"The prosecutor is not independent because he gets his orders from the Justice Minister, and his career is in the minister's hands", said Matthieu Bonduelle, Secretary General of Magistrates' Union.

The rift between the mother and the daughter came to the forefront after the daughter made claims of her mother's fraudulence.

Those claims have now triggered an inquiry into the alleged tax evasion, assault of privacy and campaign-funding law violations since 2007.

Looking at the complications in the case, the experts have opined that there is a need of appointing an investigator judge for resolving the case.