A top French magistrate who has spent years investigating allegations of wrongdoing by President Jacques Chirac and other top politicians says he is resigning. The announcement has unleashed a debate in France on whether the justice system is free and fair.

In an interview published in the French newspaper Le Parisien, French investigating magistrate Eric Halphen said years of blocked investigations had left him bitter about the French justice system. He said he had lost his idealism that real justice existed. Mr. Halphen, who has previously refused interviews with the press, said he was finally speaking out to defend his honor, after being criticized for his record.

Judge Halphen gained considerable fame in France for pursuing a series of high-level political investigations. They include allegations of kickbacks benefiting the former mayor of Paris, Jean Tiberi, who was kicked out of the conservative Rally for the Republic Party, but never formally charged.

The most sensational inquiry focused on suspicions that President Jacques Chirac may have presided over illegal party financing during his tenure as Paris mayor.

Mr. Chirac has adamantly denied the allegations.

Last year, Judge Halphen summoned President Chirac for questioning as a witness in his investigation. Mr. Chirac refused, citing his immunity as a sitting president. And only a few months ago, France's highest court ruled in the president's favor. Judge Halphen was removed from the case in September.

Judge Halphen's office did not respond to a call today, but news the Judge was quitting has stirred a furor in France. A number of French magistrates said they were shocked at Mr. Halphen's departure. That included Jean-Marie Coulon, president of the Paris appeals court. Mr. Coulon said during a radio interview that French judges are operating in a system that sometimes blocks them from acting independently.

But others believe that France's Napoleonic justice code gives investigating magistrates like Judge Halphen enormous power to both investigate and to try cases.

Judge Halphen told Le Parisien that he planned to write a book of his experiences as investigating magistrate during the 1990's.