JAKARTA: Indonesia has found the cockpit voice recorder from a Lion Air plane more than two months after the Boeing 737 MAX jet crashed into the sea near Jakarta, killing all 189 on board, an official said on Monday.
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 8m of mud in waters about 30m deep.
"We don't know what damage there is, it has obvious scratches on it," Nugroho said.
READ: Indonesian rescuers retrieve body parts from Lion Air crash site
Haryo Satmiko, deputy head of Indonesia's National Transportation Safety Committee (NTSC), told AFP that the recorder was "broken into two pieces" but hoped it was "still useful" to investigators.
More human remains were also found near the voice recorder, he added, without giving details.
"We're thankful and grateful that they have found the CVR, but it's not enough," said Evi Samsul Komar, whose son and nephew were on the fatal flight.
"There are still many passengers unaccounted for."
The cockpit voice recorder is one of two so-called black boxes crucial for the investigation of a plane crash.
The other black box, the flight data recorder, was recovered three days after the crash.
The flight data recorder gathers information about the speed, altitude and direction of the plane with enough storage for 25 hours of data, while the cockpit voice recorder keeps track of pilots' conversations and other sounds in the cockpit.
"This will really help the investigation ... and could give some more answers on the cause" of the crash, said Jakarta-based aviation analyst Dudi Sudibyo.
Investigators brought in a navy ship for a renewed search effort on Jan 8 to find the cockpit voice recorder after the plane crashed into the Java Sea in October.
The crash was the world's first of a Boeing 737 MAX jet.
Separately, Colonel Johan Wahyudi told Metro TV the recorder had been retrieved and taken aboard the ship.
Contact with flight JT610 was lost 13 minutes after it took off on Oct 29 from the capital Jakarta heading north to the tin-mining town of Pangkal Pinang.
Investigators said Lion Air kept putting the plane back into service despite repeatedly failing to fix a problem with the airspeed indicator, including on its second-last flight from Bali to Jakarta.
Black box data showed the plane also had an airspeed indicator issue on multiple earlier flights.
The plane had also flown erratically during a flight the previous evening when it experienced a "technical problem", according to data from flight-tracking website FlightRadar24.
"The plane was no longer airworthy and it should not have kept flying," Nurcahyo Utomo, aviation head at the National Transport Safety Committee, told reporters.
Following the incident, Indonesian rescuers began retrieving body parts from the crash site. There were 178 adult passengers, one child, two infants, two pilots and six cabin crew on board.
Authorities eventually called off the grim task of identifying victims of the crash in November, with 125 passengers officially recognised after testing on human remains that filled some 200 body bags.