Indonesian officials have retrieved the crashed AirAsia flight QZ8501's cockpit voice recorder which is expected to contain the pilots' conversation during the final minutes before the plane went down throwing light on the cause of the tragedy.

The flight's cockpit voice recorder, commonly referred to as black box, is currently on an Indonesian naval vessel, said the country's transport minister.

The recovery of the instrument comes a day after the flight data recorder, another section of the black box, was found by authorities.

"This is good news for investigators to reveal the cause of the plane crash," Tonny Budiono, senior official at Indonesia's transportation ministry, said.

The recorder was said to be found beneath large debris of the aircraft.

Both these equipment may provide clues to what went on in the aircraft before it crashed in Indonesian waters in the Java Sea as it was en route to Singapore. Of the 162 people on board, there were no survivors and rescue personnel have recovered only 48 bodies as yet.

The aircraft's fuselage, which is expected to contain most victims' bodies, has not yet been found.

Meanwhile, AirAsia CEO Tony Fernandes has sent a mail to the airlines' customers thanking them for their support during the tragedy.

"The past few weeks have been the most difficult weeks of my life since starting AirAsia 13 years ago. I wanted to reach out and thank you for the warmth and support given to all of us. Your messages of love and encouragement strengthen our resolve to be better. We will continue to provide updates as the investigation goes on."