Former French President Nicolas Sarkozy has been taken into police custody for questioning over allegations that he received campaign funding from the late Libyan leader Col Muammar Gaddafi.
Police are investigating alleged irregularities over the financing of his 2007 presidential campaign.
Police have questioned him previously. A former aide, Alexandre Djouhri, was arrested in London recently.
Mr Sarkozy failed in a bid to return to power in 2012.
Judicial sources said he was being questioned in Nanterre, a suburb in western Paris.
In 2013 France opened an investigation into allegations that his campaign had benefited from illicit funds from Gaddafi. Mr Sarkozy has denied wrongdoing.
The sources said one of Mr Sarkozy's former ministers and a close ally, Brice Hortefeux, was also being questioned by police on Tuesday.
The allegations came from a French-Lebanese businessman, Ziad Takieddine, and some former Gaddafi regime officials.