The cockpit voice recorder of the Lion Air jet that crashed into the Java Sea in October has been found by navy divers, an Indonesia official has said.
The pilot had asked air traffic control for permission to turn back to the airport but then contact was lost.
"We got confirmation this morning from the National Transportation Safety Committee's chairman", Djamaluddin said.
Authorities called off the grim task of identifying victims of the crash in November, with only 125 people officially identified after tests on human remains that filled some 200 body bags.
Naval Lieutenant Colonel Agung Nugroho told Reuters a weak signal from the recorder had been detected for several days and that it had been found buried in about 8 metres (26 ft) of mud in waters about 30 metres deep. He said the voice recorder's signal, created to last 90 days following a crash, would've stopped in about 15 days.
He added that the recorder had "obvious scratches on it", but that it was unclear what damage it had suffered.
The cockpit voice recorder is one of the two so-called black boxes crucial for the investigation of a plane crash.
Black box data help explain almost 90 percent of all crashes, according to aviation experts.
The discovery of the device Monday, more than two months after the crash, is a significant breakthrough for investigators trying to piece together the final moments of the brand-new Boeing 737.
The anti-stalling system repeatedly forced the plane's nose down, despite efforts by pilots to correct this.
After investigators said the doomed aircraft had problems with its airspeed indicator and angle of attack (AoA) sensors, Boeing to issue a special bulletin telling operators what to do when they face the same situation.