Outgoing French leader Nicolas Sarkozy will face a slew of legal probes into corruption and campaign financing violations after he leaves office next week and loses his presidential immunity.

France's President Nicolas Sarkozy waits for European Council President Herman Van Rompuy at the Elysee Palace in Paris, May 9, 2012. [Photo/Agencies]

Sarkozy could face questioning as soon as mid-June because he will lose his immunity a month after his successor, Socialist Francois Hollande, is sworn in on May 15.

The outgoing leader has denied any wrongdoing in a raft of cases, but the conviction last year of his predecessor Jacques Chirac on graft charges has shown that French courts are now willing to go after former leaders.

"In the past the kind of behavior that Nicolas Sarkozy is accused of was very common, but the courts did not launch prosecutions," said Philippe Braud, a political analyst at the Paris-based Center for Political Studies.

"Things have very much changed. The courts have become more courageous."

The most immediately dangerous case for Sarkozy involves a series of overlapping inquiries surrounding alleged illegal campaign financing by L'Oreal heiress Liliane Bettencourt, France's richest woman.

Magistrates are investigating claims that Bettencourt's staff handed over envelopes stuffed with cash to Sarkozy aides to finance his 2007 campaign, with her former bookkeeper testifying to one 50,000 euro ($65,000) donation.

Under France's electoral code, individual election campaign contributions may not exceed 4,600 euros.

Sarkozy and his camp have also been accused of ordering an illegal police investigation to identify an official leaking information on the Bettencourt scandal to a journalist from the newspaper Le Monde.

Judges have charged both a prosecutor close to Sarkozy and the head of France's domestic intelligence agency, Bernard Squarcini, with having illegally obtained the journalist's mobile phone logs in 2010.

Another high-profile case is the so-called "Karachi Affair", in which two close aides to Sarkozy were charged by judges investigating alleged kickbacks on a Pakistani arms deal.

In more serious but harder to prove allegations, magistrates are probing whether a 2002 Karachi bombing that killed 11 French engineers was revenge for the cancellation of bribes promised to Pakistani officials.

Claims were made that former Libyan strongman Muammar Gadafy's regime financed Sarkozy's 2007 campaign to the tune of 50 million euros, but no investigation is known to have been opened.

Sarkozy has denounced that claim as "grotesque" and said he will sue French media website Mediapart over the reports.

Agence France-Presse