Investigating judges filed preliminary charges Friday against former French Prime Minister Dominique de Villepin for his suspected role in a smear campaign that targeted Nicolas Sarkozy before he was France's president, his lawyer said.

The preliminary charges were for "complicity in slanderous denunciations," de Villepin's lawyer Luc Brossollet said. The case stems from an alleged attempt in 2003-2004 to discredit Sarkozy, who was a government minister at the time and a political rival of de Villepin within their conservative UMP party.

De Villepin said he committed no wrongdoing.

"At no moment did I take part in any political manoeuvring," de Villepin said after seeing the judges.

The bizarre, complex case has shaken France's political world to the core and tainted the reputation of de Villepin, once the rising star of France's conservative circles of power.

The scandal started simmering when a judge received a mysterious CD-ROM accusing Sarkozy and other top ministers of holding secret accounts with Luxembourg bank Clearstream. The bank accounts were purportedly created to hold bribes from a 1991 sale of frigates to Taiwan.

But investigators realized the scheme was a hoax and turned their attention to uncovering the culprits.

Investigating judges Henri Pons and Jean-Marie d'Huy suspect de Villepin of a role in the scheme to discredit his rivals — including Sarkozy, who already had his sights on France's highest office at that point. Villepin was also believed to have presidential ambitions then, before his popularity plunged during strikes and protests over a labour law he pushed for last year.

De Villepin's legal team said he was not answering in-depth questions Friday.

"He has never had access to the dossier before — today, there are 26 tomes (of documents) — and it's a dossier that deserves to be analyzed with a fresh eye," his lawyer Olivier d'Antin said. "He informed the judge that he was ready to respond to questions once he had knowledge of the dossier."

De Villepin has said his actions were "strictly in the framework" of his jobs as foreign minister and interior minister at the time. He has also claimed he was targeted in the case.

"I was the victim … of slander and lies," de Villepin said in December, after his initial hearing in the case, which lasted 17 hours.

De Villepin left his job as premier in May when Sarkozy replaced Jacques Chirac. Soon afterward, investigators searched de Villepin's home and office in the investigation after the discovery of his name in computer files belonging to a Defence Ministry official, Gen. Philippe Rondot. Rondot wrote in his notes that two key players in the affair told him they acted on orders from de Villepin.

Under French law, a minister or former minister has the right to argue that he should be judged by the special Court of Justice, which tries officials accused of wrongdoing in their functions.

Among issues to be determined is whether de Villepin would have acted in his capacity as a minister — as he contends. De Villepin could, in theory, contest the charges, though it was not immediately clear if he would do so.

Before serving as premier, de Villepin also served as foreign and interior minister under Chirac. His international moment of glory came in a 2003 speech before the UN Security Council, where he made an eloquent case against the U.S. war in Iraq.