A judge on Thursday filed preliminary charges against former President Nicolas Sarkozy in a campaign finance case, formally placing him under investigation over allegations that he illegally took donations from France’s richest woman on way to his 2007 election victory.

The preliminary charges were issued against Sarkozy after he went through hours of questioning in a Bordeaux courthouse, according to the prosecutor’s office. The ex-president is accused of “abuse of someone in an impaired state” in the case involving L’Oreal cosmetics fortune heiress Liliane Bettencourt, who is now 90.

Under French law, preliminary charges mean the investigating magistrate has reason to believe wrongdoing was committed, but allows more time to investigate. The charges may later be dropped or could lead to a trial.

The investigation centers on the finances of Bettencourt, who was once the focus of a long-running family feud over her fortune. Bettencourt, who was reported to suffer from Alzheimer’s disease, has since been placed under legal protection.

In November, Sarkozy was given the status of a so-called “assisting witness,” with the possibility of facing charges later on allegations of abusing someone in an impaired state, swindling and abuse of confidence.

After Thursday’s questioning, a three-judge panel opted only to retain only the first of those counts related to activity in February 2007 and throughout that year, according to the prosecutors’ office. It emphasized that the former president is still presumed innocent of any wrongdoing.

Investigating judge Jean-Michel Gentil was looking into conflicting accounts about how many times Sarkozy _ a darling of the mainstream political right _ visited the home of Bettencourt in the run-up to his winning 2007 campaign for president, according to one lawyer.

Earlier in the probe, Bettencourt’s ex-accountant told police she gave 150,000 euros ($192,000) to the manager of Bettencourt’s fortune that was to be passed on to Sarkozy’s campaign treasurer.

“If Mr. Gentil placed Mr. Sarkozy under investigation this evening it’s because he had a reason to do so,” said Antoine Gillot, a lawyer for Bettencourt’s former butler, who was also questioned Thursday along with Sarkozy, on French TV i-Tele. “It was a semi surprise ... it means the judge has a certain number of facts.”

Sarkozy lost his legal immunity from prosecution when he failed to win re-election. Socialist Francois Hollande defeated him for the presidency in May. Sarkozy’s lawyer and spokeswoman didn’t return calls, e-mails or text messages from The Associated Press seeking comment.

Thierry Mariani, a lawmaker and ally in Sarkozy’s conservative party, suggested the charges were politically motivated and part of an effort to discredit Sarkozy just as polls suggest he is still widely liked and show big disappointment in Hollande, his successor. (AP)