A French prosecutor has asked for charges to be dropped against former President Nicolas Sarkozy in an investigation into his campaign finances.

Sarkozy is accused of "abuse of someone in an impaired state" over allegations he took donations for his 2007 presidential run from L'Oreal cosmetics fortune heiress Liliane Bettencourt, who is in her 90s. After Friday's request by the Bordeaux prosecutor's office, a judge still needs to decide if the case will be dropped.

A web of politicians, financial advisers and lawyers has been drawn into the investigation into whether there was a conspiracy to defraud France's richest woman. Bettencourt's ex-accountant told police she gave 150,000 euros ($192,000) to be passed on to Sarkozy's campaign treasurer.

Sarkozy, who lost his re-election campaign last year, has maintained his innocence.