Former French President Nicolas Sarkozy, 59, is formally under investigation on allegations of misuse of his political power. The country's former ruler was "mis en examen" in a Paris court Tuesday, after 15 hours of police questioning.

The Paris court had summoned Sarkozy to appear after allegations surfaced the he directly or indirectly used his position to gleam information on legal proceedings against him. The term "mis ex examen" has no exact equivalent in U.S. legal system, but is most likened to being charged or arraigned. In France, only an investigating judge can place a suspect under formal investigation.

Sarkozy, along with his lawyer Thierry Herzog and a French magistrate, is officially being investigated for corruption and misuse of influence. Abuse of power under French law carries a sentence of up to five years in prison and a fine of up to 500,000 euros, or $684,000.

Investigators will try to discern if Sarkozy tried to obtain information about any of the six current legal cases in which he is involved. The central case of concern surrounds illegal campaign donations for his 2007 successful presidential bid. The investigation will also cover the financing of his unsuccessful 2012 re-election campaign, which he lost to François Hollande.

In March, the newspaper La Monde revealed an operation in which authorities had been tapping phone communications between the president, Mr. Herzog and two former ministers of Sarkozy for an entire year.

Sarkozy denies any wrongdoing in these matters. This comes as a blow to the hope of his supporters that Sarkozy would take another run for president in 2017.

"These events only rely on phone taps...whose legal basis will be strongly contested," Paul-Albert Iweins, who represents Herzog in the case, told Liberation, a French newspaper.

Under French criminal law, a formal investigation can take months, since it requires appointing a judge who leads a thorough inquiry of all allegations.