The two "black boxes" could supply key clues as to why the Sriwijaya Air Boeing 737-500 plunged about 10,000 feet (3,000 metres) in less than a minute before slamming into the Java Sea soon after take-off on Saturday, taking with it 62 people.

Divers just off the coast of Jakarta had hauled the data recorder to the surface Tuesday, with the hunt now focused on finding a voice recorder on the wreckage-littered seabed.

The discovery came as a team from the US National Transportation Safety Board (NTSB) prepared to join the investigation in the capital, along with staff from Boeing, the Federal Aviation Administration and jet engine producer GE Aviation.

While dozens of boats and helicopters searched for wreckage, poor conditions forced divers to temporarily suspend their hunt.

"It was called off...due to bad weather. All divers are now on standby," said National Search and Rescue Agency (Basarnas) spokesman Yusuf Latif.

A remotely operated underwater vehicle was still searching the wreckage-littered seabed.

Agency chief Soerjanto Tjahjono said a day earlier that investigators hoped to download data from the retrieved black box in a matter of days, so "we can reveal the mystery behind this accident".

Black box data includes the speed, altitude and direction of the plane as well as flight crew conversations, and helps explain nearly 90 percent of all crashes, according to aviation experts.

So far authorities have been unable to explain why the 26-year-old plane crashed just four minutes after setting off from Jakarta, bound for Pontianak city on Borneo island, a 90-minute flight away.

Grisly search

More than 3,000 people are taking part in the recovery effort, assisted by dozens of boats and helicopters flying over small islands off the capital's coast.

"It's not easy to find victims and parts of the fuselage because the debris and human remains are usually in small pieces so they can easily drift away," said Agus Haryono with the Basarnas' crash team.

Navy divers prepare to go under during recovery operations for the ill-fated Sriwijaya Air Boeing 737-500 passenger aircraft near Lancang Island on January 10, 2021, following the January 9 crash of flight SJ182 into the Java Sea minutes after takeoff. (Agence France Presse/Adek Berry)

The grisly task of hunting for mangled body parts can also take a psychological toll.

Newer divers "feel uncomfortable or even get scared, especially when they're retrieving remains at night," Haryono said.

"But, as time goes by, they get stronger mentally to face these situations."

Three more victims have been identified by matching fingerprints on file to body parts retrieved from the murky depths, authorities said Wednesday, including a 50-year-old female passenger and a 38-year-old off-duty pilot.

There were 10 children among the passengers on the half-full plane, which had experienced pilots at the controls.

Scores of body bags filled with human remains were being taken to a police morgue where forensic investigators hoped to identify victims by matching fingerprints or DNA with relatives.

Deadly dive

Authorities said the crew did not declare an emergency or report technical problems with the plane before its dive, and that the 737 was probably intact when it hit the water -- citing a relatively small area where the wreckage was scattered.

The crash probe was likely to take months, but a preliminary report was expected in 30 days.

Rescue workers inspect recovered debris at the port in Jakarta on January 10, 2021, during the search operation for Sriwijaya Air flight SJY182 which crashed after takeoff from Jakarta on January 9. (Agence France-Presse/Dany Krishnadhi)

Aviation analysts said flight-tracking data showed the plane sharply deviated from its intended course before it went into a steep dive, with bad weather, pilot error or mechanical failure among the potential factors.

The accident has spawned some misinformation online, including a pair of pictures claiming to show a baby who survived the weekend crash. The images actually show an infant rescued from a fatal 2018 boat disaster.

Sriwijaya Air, which flies to destinations in Indonesia and across Southeast Asia, has had safety incidents including runway overruns.

But it has not had a fatal crash since starting operations in 2003.

Its CEO has said the jet, which was previously flown by US-based Continental Airlines and United Airlines, was in fit condition.

Indonesia's fast-growing aviation sector has long been plagued by safety concerns, and its airlines were once banned from US and European airspace.

In October 2018, 189 people were killed when a Lion Air Boeing 737 MAX jet crashed near Jakarta.

That accident -- and another in Ethiopia -- led to the grounding of the 737 MAX worldwide over a faulty anti-stall system.

The 737 that went down Saturday was first produced decades ago and was not a MAX variant.