Officials in Indonesia say rescuers have found the cockpit voice recorder from a Lion Air jet that crashed into the Java Sea in late October, killing all 189 people on board.

Ridwan Djamaluddin, a deputy maritime minister, told reporters on Monday that the National Transportation Safety Committee (KNKT) had informed the ministry about the recovery.

He added that human remains were also discovered at the seabed location.

Naval Lieutenant Colonel Agung Nugroho told the Reuters news agency a weak signal from the recorder had been detected for several days and that it had been found buried in about eight metres of mud in waters about 30 metres deep.

"We don't know what damage there is, it has obvious scratches on it," Nugroho said.

The cockpit voice recorder is one of the two so-called "black boxes" crucial for the investigation of a plane crash.

Investigators have already recovered the flight data recorder from the Boeing 737 Max, which provided information about the speed, altitude and direction of the two-month-old jet that plunged into the Java Sea just minutes after taking off from the capital, Jakarta, on October 29.

The preliminary crash report from Indonesian authorities suggested that pilots of Flight 610 struggled to control the plane's anti-stalling system immediately before the crash.

Investigators also found that the Lion Air jet should have been grounded over a recurrent technical problem before its fatal journey, but did not pinpoint a cause of for the accident.

A final crash report is not likely to be filed until later this year.

Black boxes

Despite the name, black boxes are usually bright orange with reflective stripes, and all commercial planes are obliged to have them on board.

They're built to survive at vast depths and in extreme heat, and are fitted with a beacon which can emit a signal for one month.

Black box data help explain nearly 90 percent of all crashes, according to aviation experts.

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.

Following requests from victims' families, Lion said in December it would allocate 38 billion rupiah ($2.6m) to hire a Dutch company to continue the search with its ship the MPV Everest.

Nearly 30 relatives of the crash victims have filed lawsuits against Boeing, alleging faults with the new model 737 MAX led to the deaths.

The single-aisle Boeing plane is one of the world's newest and most advanced commercial passenger jets.

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.

An AOA sensor provides data about the angle at which air is passing over the wings and tells pilots how much lift a plane is getting. The information can be critical in preventing an aircraft from stalling.

The plane's flight data recorder showed that pilots had repeatedly tried to correct its nose from pointing down, possibly after erroneous data from AoA sensors was fed into a system that automatically adjusts some of its movements.