Indonesian divers have recovered the flight data recorder of the crashed AirAsia plane, which is believed to be at the bottom of the Java Sea.

The second part of the black box, the cockpit voice recorder has also been located, but divers have not reached it yet, the BBC reports.

AirAsia flight QZ8501, which was on a route from Surabaya to Singapore, disappeared on 28 December 2014 above the Java Sea with 162 people on board.

The search crews have recovered dozens of bodies, but the majority of the victims are believed to be contained in the fuselage, which has not been found yet.

The flight data recorder will reveal information such as the condition of the engine, the altitude of the plane and what the pilots were doing, which should be of help when establishing the cause of the crash.

Although Indonesia has declared its capacity to analyse the two parts of the black box, it is believed that international teams will also be involved.

The head of Indonesia's search and rescue agency Bambang Soelistyo announced that the flight data recorder was found under the wreckage of a wing.

The black box is usually placed in the rear of the plane and is designed to withstand a crash and being submerged in water.

An operations coordinator of Indonesia's search and rescue agency raised a hypothesis that the plane could have exploded when landing on the water.

The tail of the plane was retrieved, but the international search for the remaining missing passengers and the fuselage continues.