Air France received a false bomb threat for a flight from Argentina to Paris days before a plane went missing over the Atlantic, an airline spokesman has said.
The revelation came as military planes battled bad weather at sea to located more debris from flight AF447, which plunged into the ocean.
France's defence minister earlier said there was "no signs" of terrorism regarding the crash on the Airbus 330 from Rio de Janeiro to Paris.
The reason for the crash remains unclear, with fierce thunderstorms, lightning or a catastrophic combination of causes as possible theories.
But Air France spokesman Nicolas Petteau has said the airline's agency in Buenos Aires received an anonymous phone call threatening flight 415, which was flying from the city to Paris.
The plane, a Boeing 777, was checked by security services who found it to be a false alert and the plane was allowed to leave, he said.
France's defence minister Herve Morin said "we have no signs so far" of terrorism regarding the plane that disappeared after leaving Brazil on Sunday, but he said all hypotheses must be studied.
Meanwhile, military planes and ships have located more debris from the jet, but high seas and heavy winds have been slowing the recovery effort
Search vessels pushed toward the floating debris, including a 23-foot chunk of plane and a 12-mile-long oil slick. No signs of life or bodies have been found.
Earlier, the head of France's accident investigation agency said he is "not optimistic" that rescuers could recover the plane's black boxes and said investigators should be prepared to continue the probe without them.