Former French President Nicolas Sarkozy is being held for questioning over suspicions he received leaked details of an inquiry into alleged irregularities in his 2007 election campaign.
It is the first time a former head of state had been held for questioning in modern French history and is the latest blow to Sarkozy's hopes of a come-back after his 2012 election defeat by Francois Hollande.
The conservative politician denies all wrong-doing in a string of investigations involving him.
Asked about the matter, government spokesman Stephane Le Foll said Sarkozy was "subject to justice like everyone else."
More top news
Researchers in Boston have created a 'robot cheetah' that they hope will be able to reach top speeds of 30mph.
UK trials of a vaccine for the Ebola virus began today - but some experts complain that the response has been a long time coming.
This September has been the driest so far for more than 50 years, Met Office figures have revealed.