French ex-President Nicolas Sarkozy has been placed under formal investigation in a probe into his campaign funding, prosecutors say.
It relates to spending in his unsuccessful 2012 bid for re-election when his campaign costs were more than twice the legal limit.
Mr Sarkozy, 61, was questioned all day on Tuesday by magistrates before being informed he was under investigation.
He has repeatedly denied knowledge of the overspending.
He has said he was not involved in the details of his campaign finance.
Judges are investigating claims that the party faked invoices worth 10m euros (£7.8m; $11.1m) during the 2012 presidential campaign to cover increasing costs.
Mr Sarkozy is the head of France's centre-right Les Republicains political party (previously the UMP) and was the president of France from 2007 to 2012.