The affair, which the opposition Socialists used to attack Charles Pasqua, the blunt Gaullist Interior Minister, also threatened to expose tensions within the Gaullist RPR party, where some members made plain their differences with the conservative government of Edouard Balladur.
The ministry said it had removed Claude Bardon, the head of the Paris section of the Renseignements Generaux, France's equivalent of the Special Branch, and Bertrand Michelin, who headed the department dealing with political parties, from their posts. They were not, however, sacked outright from the police and can expect to be named to new, if less senior jobs.
The affair was revealed by Le Canard Enchaine, the satirical and investigative weekly which makes a habit of exposing official abuse, in its latest issue on Wednesday.
It described how a Renseignements Generaux officer, through a friend who was a technician working at the closed meeting of the Socialists' national council in Paris on 19 June, had access to a an interpreters' booth. The booth was equipped with a working telephone and the officer, who was there incognito, was able to provide live commentary on the meeting to Mr Michelin.
At the session, Michel Rocard, a former prime minister, was removed as party first secretary because of his disastrous performance in the European elections the previous weekend.
According to Le Canard, while the presence of Renseignements Generaux personnel at public political meetings is common - usually to gauge attendance and keep an eye on political militants - the officer's clandestine use of the booth at a confidential meeting was illegal and Mr Michelin should have told him to stop.