Under the laws of France, official examination is the final step before a suspect facing criminal charges.
Sarkozy, who in March hinted at the possible return to politics, has repeatedly denied receiving campaign funds from Bettencourt.
"Nicalas Sarkozy, who have benefited from the presumption of innocence, has been told that he had been subject to official examination due to take advantage of vulnerable people in February 2007 and during 2007 due to the detriment of Liliane Bettencourt," said public prosecutor after a review process.
Bettencourt, who is 90 years old, was the richest woman in France.
Sarkozy, who was defeated in the general election last year from Francois Hollande, the find annggota in the process of examination of Bettencourt's staff on Thursday morning, Reuters said.
He was questioned by the judges in November, but they chose not to open the big checks against Sarkozy, who lost in the world of politics but still be a candidate that might appear from the conservative strongholds in the coming presidential election in 2017.
Early suspicions about funds stuck out three years ago, when a woman who works as an accountant for Bettencourt, who is mentally fragile, suspect a lot of money taken for Sarkozy's presidential election campaign.
Bettencourt is revealed to be the condition dementia in 2006 and placed under the supervision of his family in 2011.
The TV station France, BFM, citing lawyer Sarkozy, reported the decision was "chaotic and unfair" and he will appeal, according to Reuters.
Translator: Chaidar Abdullah
News; Finance; Insurance; Health; Cancer
News; Finance; Insurance; Health; Cancer; Car Insurance; Health Insurance
