Welcome to our live coverage of the dramatic developments surrounding former French President Nicolas Sarkozy. The man widely tipped as the centre-right's candidate for the next election, in 2017, has been detained near Paris for questioning over suspected influence-peddling. Stay with us for news updates, correspondent analysis and readers' comments.
Here is Mr Sarkozy in a photo from 9 March 2012, when he was still president, campaigning for re-election in the southern city of Nice.
07:26 Hugh Schofield, BBC News, Paris
The investigators who are holding Mr Sarkozy believe they can build a case to show he had a judge working on his behalf in the highest court in France, the Cour de Cassation. It's alleged that in advance of an important decision earlier this year - over whether Mr Sarkozy's work diaries should be kept in the hands of the justice system - this judge not only kept Mr Sarkozy informed of proceedings, but may even have tried to influence other judges.
07:30 Hugh Schofield, BBC News, Paris
Mr Sarkozy says the allegations against him are politically motivated. What's clear is they represent another obstacle in the way of his planned return to frontline politics.
French judge Gilbert Azibert, seen here in July 2008, has also been called in for questioning.
French government spokesman Stephane Le Foll told iTele that Mr Sarkozy was "subject to justice just like everyone else".
"Justice authorities are investigating and have to go all the way."
This current case is one of six legal investigations involving Mr Sarkozy. They include a new one activated this year into separate irregularities in his unsuccessful 2012 election campaign.
The former leader is due to be questioned for four hours, France's Le Figaro daily reports. He arrived himself this morning at the anti-corruption office of the judicial police, which is in Nanterre, near Paris. Mr Sarkozy's interrogation comes soon after his lawyer, Thierry Herzog, was placed in police custody, the paper notes.
Mr Sarkozy was formally placed in custody this morning for procedural reasons, Le Figaro explains. However, it points out, this is an unprecedented step.
Among the other investigations that he is subject to, Mr Sarkozy is also the focus of an inquiry launched in February. That is investigating whether he sought to use his influence to obtain information about a separate inquiry, into allegations that late Libyan leader Muammar Gaddafi funded his 2007 election campaign.