Magistrates delving into corruption allegations against Nicolas Sarkozy put the former French president under official investigation late Tuesday.

Sarkozy was “mis en examen,” the equivalent of being charged, over allegations that he directly or indirectly abused his power in an attempt to find out information about legal investigations against him.

The decision, described by the French economic paper Les Echos as a “spectacular measure,” is a serious blow to Sarkozy, 59, who is believed to be planning his political comeback for the 2017 presidential election. It came after the former leader, who has always vigorously denied any wrongdoing, was quizzed by investigators at a police station on the outskirts of Paris for more than 15 hours Tuesday.

Sarkozy's lawyer, Thierry Herzog, and a French magistrate are also now under official investigation. The two men have been accused of attempting to violate the secrecy of a legal inquiry.

Detectives will now try to establish whether Sarkozy and the others tried to obtain confidential information about an investigation into whether Sarkozy received illegal campaign donations for his successful 2007 presidential bid, including from former Libyan dictator Moammar Kadafi and France's richest woman Liliane Bettencourt, the L'Oréal heiress.

During their investigation, detectives tapped the phones of Sarkozy and Herzog. The two were allegedly heard discussing an attempt to get information about the case from a magistrate in return for offering him a high-level position in Monaco.

Investigators are also looking into the financing of Sarkozy's unsuccessful 2012 presidential campaign, which he lost to the Socialist Fran¿¿ois Hollande.
Willsher is a special correspondent.