This is really funny. Australia and Malaysia has reached a deal on who should have the custody of the black box, once it is recovered. Why a deal even before recovering the black box?

The initial search and rescue response, crash recovery operation, and resulting investigation by the Government of Canada took over four years and cost CAD 57 million (at that time approximately USD 38 million).[3] The Transportation Safety Board of Canada's (TSB) official report of their investigation stated that flammable material used in the aircraft's structure allowed a fire to spread beyond the control of the crew, resulting in a loss of control and the crash of the aircraft.[4]

While the Brazilian Navy removed the first major wreckage and two bodies from the sea within five days of the accident, the BEA's (Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile) initial investigation was hampered because the aircraft's black boxes were not recovered from the ocean floor until May 2011, nearly two years later.[1][3]

Underwater search
On 5 June 2009, the French nuclear submarine Émeraude was dispatched to the crash zone, arriving in the area on the 10th. Its mission was to assist in the search for the missing flight recorders or "black-boxes" which might be located at great depth.[95] The submarine would use its sonar to listen for the ultrasonic signal emitted by the black boxes' "pingers",[96] covering 13 sq mi (34 km2) a day. The Émeraude was to work with the mini-sub Nautile, which can descend to the ocean floor. The French submarines would be aided by two U.S. underwater audio devices capable of picking up signals at a depth of 20,000 ft (6,100 m).[97]