Moscow, June 24 (RIA Novosti) Signals from the flight data recorders of the Air France jet that crashed into the Atlantic killing all 228 people on board have been located, a media report said Tuesday.

The Le Monde newspaper said French naval vessels had picked up a weak signal from the flight recorders at the site of the June 1 crash. The paper did not give the source of the information.

The report said a mini-submarine had been dispatched Monday to try to find the black boxes on the ocean floor. The devices may contain information on what caused the crash of the Airbus A330 en route from Rio de Janeiro to Paris.

“The search effort has been complicated by the uneven surface of the ocean floor. The depth at the site is almost 5,000 meters (16,400 feet),” the paper said.

Air France said it could not confirm the report.

Beacons on the recorders send an electronic impulse every second for at least 30 days. The signal can be picked up from two kilometres away.

French vessels involved in the search operation include a nuclear submarine with advanced sonar equipment and a research ship equipped with mini submarines.

Ten of the 50 bodies recovered from the plane have been identified as Brazilians.