TEAMS have retrieved one of the black box recorders of an Air France jet that crashed into the ocean in 2009.

It's hoped the discovery will help solve the mystery of why the state-of- the-art passenger plane went down in the Atlantic, while on a Rio-Paris flight.

"The investigation team located and identified the memory unit from the Flight Data Recorder (FDR) this morning," said France's Bureau of Investigation and Analysis (BEA), which has been charged with probing the disaster that killed 228 people.

In a statement, the agency added that the device was "in good physical condition" after it was "raised and lifted by the Remora 6000 ROV (robot submarine) on board the ship Ile de Sein."

Investigators announced Wednesday that search teams had retrieved part of a black box flight recorder from the Airbus A330, but not the part containing the key data.

BEA said the chassis that held one of the recorders was found a day after a salvage ship began working to retrieve bodies and recently discovered wreckage using the Remora submarines.

Originally published as Air France black box recovered