E x-French President Nicolas Sarkozy has been placed under formal investigation over alleged influence peddling.
French ex-President Sarkozy held over influence claims
He appeared before a judge in Paris late on Tuesday after 15 hours of questioning by anti-corruption police.
This is thought to be the first time a former French head of state has been held in police custody.
Mr Sarkozy's lawyer, Thierry Herzog, and a magistrate, Gilbert Azibert, were also placed under formal investigation over the same allegations.
A second magistrate called in for questioning, Patrick Sassoust, had not appeared before a judge as of Tuesday night.
When a suspect is placed under formal investigation, he or she is then examined by a judge, who determines whether there is sufficient evidence for the suspect to be charged.
The step often, but not always, leads to trial. Influence-peddling can be punished by up to five years in prison and a fine of 500,000 euros (£400,000; $684,000).
'Not a lot'
Mr Sarkozy was released from custody around midnight (22:00 GMT) after appearing in court in Paris.
He had been brought to the court from the judicial police office in Nanterre, west of the French capital, where he had been interrogated.
Paul-Albert Iweins, the lawyer representing Mr Herzog, said the case rested only on "phone taps... whose legal basis will be strongly contested".
"There's not a lot in this dossier, since none of the material elements of what I've seen, and what we could contest, support the accusations," he added.
The inquiry arose out of a separate investigation into whether Mr Sarkozy had received illegal funding for his election campaign in 2007 from the late Libyan leader, Muammar Gaddafi.
Mr Sarkozy is hoping to challenge again for the presidency in 2017 and the inquiry is seen as a blow to his hopes of returning to office.
Investigators are trying to find out whether Mr Sarkozy, 59, who was president from 2007 to 2012, had promised a prestigious role in Monaco to Mr Azibert, in exchange for information about an investigation into alleged illegal campaign funding.
They are looking into claims that Mr Sarkozy was warned his phone was being bugged as part of the Gaddafi inquiry.
Mr Sarkozy's predecessor, Jacques Chirac, was given a suspended prison sentence in 2011 for embezzlement and breach of trust while he was mayor of Paris but he was never questioned in custody.
Source: BBC