Air France says it is seeking to press charges against the culprits in a fake bomb scare, which forced a flight from Mauritius to Paris to make an emergency landing in Kenya.
A spokeswoman for the airline said on Monday that the hoax had put lives in danger.
She said that the Air France desk at Charles de Gaulle airport in Paris had filed a complaint to the authorities in Bobigny, in the north-eastern suburbs of the French capital.
It remained unclear who had planted the mock device – made of paper, cardboard and a kitchen timer – in the plane’s lavatory.
Flight AF463 was headed from Mauritius to Paris on Sunday with 473 people on board when a passenger discovered the suspicious object.
The plane was subsequently diverted to the nearest airport, which was Mombasa.
The 459 passengers and 14 crew members returned to Charles de Gaulle airport on Monday, an Air France spokesman said.
Air France chief Frederic Gagey said on Sunday that there was no evidence of a safety breach on Mauritius, which is a favourite holiday destination for French nationals because a large part of the Indian Ocean island’s population can speak French.
The device did not contain any explosives and was therefore not detected by security officials there, Gagey said.