“Mr. Nicolas Sarkozy and Mrs. Carla Bruni-Sarkozy cannot accept that remarks made in private were recorded and published without their consent,” lawyers Thierry Herzog and Richard Malka said in a statement.
Critics say the move will fuel speculation that the tapes may contain something more serious that could put the breaks on a possible presidential bid for Sarkozy in 2017. He was defeated by President Francois Hollande two years ago.
Buisson made the recordings using a device in his pocket and later uploaded to his computer. He maintains the device had been stolen and that he would file a theft complaint.
Breach of privacy in France carries a penalty of up to one year in prison and 45,000 euros ($61,000) in fines.
Source: AFP, AP, dpa