President Sarkozy had an affair with the wife of one of his present Cabinet members about four years ago, when he was serving as Interior Minister, according to the former head of French police intelligence.

The alleged episode was one of a multitude of damaging secrets reported yesterday from the private notebooks of Yves Bertrand, who was central director of the powerful Renseignements Généraux (RG) spy agency for 12 years until 2004.

The police chief, whose shadowy service had long been a political tool for French rulers, also recorded in 2003: “Chirac has been for a facelift in Canada.”

The diaries, packed with potentially explosive accounts of drug-taking, illicit sex, blackmail and corruption among French leaders, were seized by judges recently as part of an investigation into dirty tricks. They were leaked to Le Point, a news magazine.

Mr Bertrand, 63, also recorded intimate details of the private life and family of Lionel Jospin, Prime Minister and candidate against President Chirac in the election in 2002.

His regular informants included journalists who were paid, said Le Point. “These notebooks are a terrifying journey under the skirts of the Republic,” said the magazine, which quoted only edited excerpts.

“One could laugh if this exercise in underhand police work had not sometimes broken careers, thwarted democracy and sometimes destroyed lives,” it said.

Key names were omitted by Le Point, but its summary of the notebooks appeared to confirm an assumption that after 2002 the RG was working for President Chirac to undermine Mr Sarkozy when he took over the Gaullist movement and made a bid for the presidency.

One of the unconfirmed reports then was that Cécilia Sarkozy, is wife, had been tipped off by the RG of his alleged infidelity.

Since their divorce the former Mrs Sarkozy, whom Mr Bertrand described as a party animal, has complained about her ex-husband's affairs.

Mr Sarkozy had Mr Bertrand removed from his post in 2004, suspecting that he was involved in an attempt by Dominique de Villepin, his Cabinet rival, to blacken his name. Prosecutors this week called for Mr de Villepin, who later became Prime Minister, to be brought to trial for complicity in Clearstream, a plot to smear public figures.

After winning the presidency Mr Sarkozy dismantled the police spy service. Internal spying is supposed to be supervised more closely under a new domestic intelligence agency, but there has already been a row about a database that was to include information on the sexual habits of public figures. Mr Sarkozy imposed limits to the database last month.

Mr Bertrand told Le Point that his notes were raw information that he had kept for his own use.

“It is normal that the boss of the RG should be kept informed at an early stage of events,” he said. “I did not write much about private lives and if I did so, it was to protect members of the government.”

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