5:07PM BST 09 May 2012

The Right-winger, who lost his re-election bid to Socialist François Hollande on Sunday, held his last cabinet meeting on Wednesday – said to be an “emotional” affair in which he urged colleagues not to be “sad or bitter”.

Telling aides he intends to retire from front line politics, Mr Sarkozy let them know he was preparing to return to his former life as a lawyer at the Paris firm he still partly owns, after taking a break with his wife Carla Bruni-Sarkozy and their baby daughter.

But the outgoing president could soon be called for questioning – either as a witness or potentially as a suspect – in several corruption cases when he loses presidential immunity a month after leaving office on May 15.

Judges are likely to want to summon him over an investigation into who ordered French intelligence to unlawfully seek to uncover the source of journalists working for Le Monde. France’s intelligence chief is currently under investigation over the affair in which Le Monde exposed embarrassing links between Mr Sarkozy’s government and Liliane Bettencourt, the l’Oréal billionaire caught up in a tax evasion and illegal party financing inquiry.

Mr Sarkozy is suspected of benefiting from brown envelopes of cash to help fund his 2007 campaign from Mrs Bettencourt and her late husband, André, whose former bookkeeper has told judges she withdrew 150,000 euros earmarked for Mr Sarkozy’s then campaign treasurer. He also faces questioning over allegations he personally accepted cash from the Bettencourts during a visit shortly before his 2007 election. Mr Sarkozy denies wrongdoing on all accounts.

Another case in which Mr Sarkozy’s name has cropped up is the so-called “Karachi affair”, a complex investigation into alleged kickbacks on arms contracts.

Judges are looking into irregularities in the financing of former Prime Minister Edouard Balladur’s 1995 presidential campaign. Mr Sarkozy was Mr Balladur’s campaign spokesman and budget minister at the time.

Magistrates suspect the Balladur camp of receiving illicit “retro-commissions” from the sale of French submarines to Pakistan. Mr Sarkozy’s best man and former ministerial cabinet chief are both under formal investigation over the affair.

A separate investigation is under way into allegations that 11 French engineers died in a Karachi bombing carried out by Pakistani agents angry after bribes from the sale were cut off. Mr Sarkozy has always denied any wrongdoing.

The most recent corruption allegation to be levelled against him is that he received 50 million euros of illegal campaign contributions from the late Muammar Gaddafi.

Last month, investigative news website Mediapart published what it said was a copy of a document signed by Moussa Koussa, Col Gaddafi’s intelligence chief in 2006 outlining the alleged funding deal. Mr Sarkozy has dismissed it as a forgery.

Saif-Al Islam Gaddafi, Gaddafi’s son and former heir, last year unambiguously claimed that Libya had funded Mr Sarkozy’s election.

Finally, he could be questioned over why his former chef de cabinet signed a lucrative contract with an opinion poll company run by a close aide of the president without going through the normal public tender procedures.

Last December, Jacques Chirac became the first post-war French head of state to be convicted of criminal wrongdoing, receiving a two-year suspended prison sentence for diverting public funds and abusing public trust.