PARIS (AP) -- Former French President Nicolas Sarkozy has been placed under investigation as a special witness after a day spent answering a judge's questions about a whether he accepted illegal campaign donations from Europe's richest woman.

After 12 hours of questioning, the prosecutor in Bordeaux Claude Laplaud confirmed to Sipa news that Sarkozy had been named a witness with the possibility of facing charges later in the case of the 90-year-old L'Oreal heiress, Liliane Bettencourt.

Sarkozy left the courthouse shortly before 10 p.m. local time, accompanied by his lawyer.

Bettencourt's former accountant told police she handed over Û150,000 ($192,000) in cash she was told would be passed on to Sarkozy's campaign treasurer. In July, a magistrate ordered the seizure of Sarkozy's diaries, including his calendars.