Former French president Nicolas Sarkozy is being held in police custody for questioning by magistrates looking into allegations of Libyan funding for his 2007 election campaign, a French judicial official has said.
The official said the 63-year-old was being detained in custody in Nanterre, west of Paris.
A lawyer for Mr Sarkozy could not be reached for comment.
France opened a judicial inquiry in 2013 into allegations that Mr Sarkozy's successful 2007 election bid benefited from illicit funds from late Libyan leader Muammar Gaddafi.
A former minister and close ally of Mr Sarkozy, Brice Hortefeux, was also questioned by police in relation to the Libya investigation, another source close to the inquiry said.
Mr Sarkozy, who served as president from 2007 to 2012, has always denied receiving any illicit campaign funding and has dismissed the Libyan allegations as "grotesque" and a "crude manipulation".
In January, a French businessman suspected by investigators of funneling money from Gaddafi to finance Mr Sarkozy's campaign was arrested in Britain and granted bail after he appeared in a London court.
Mr Sarkozy has already been ordered to stand trial in a separate matter concerning financing of his failed re-election campaign in 2012, when he was defeated by Francois Hollande.
Investigators in France can hold people for questioning for up to 48 hours before either releasing them or sending them before magistrates who decide whether they have grounds for turning a preliminary inquiry into a full investigation.
The latter can, but does not always, lead to a trial.
