Indonesian officials said Thursday that divers have recovered one of two so-called black boxes of an airliner that crashed into the Java Sea on Monday, which could shed light on what caused the loss of the plane and its 189 passengers and crew.

National Transportation Safety Committee investigator Ony Soeryo Wibowo told a press conference the navy divers retrieved the black box of Lion Air Flight JT610 from the sea floor, at a depth of 30 meters, but the search continues for the other black box.

Calling it a "crash survivable memory unit," Ony said investigators have not been able to determine whether the black box contains the flight data recorder or the cockpit voice recorder.

(Wreckage believed to be from the crash of Lion Air Flight 610 is seen at a port in Jakarta on Oct. 29, 2018)

"The label of the black box has gone missing, while the two black boxes actually look similar, so we need to check in our laboratory whether the black box contains the FDR or the CVR," he said.

When it was found, the orange-colored item was broken in half, with the other half missing.

"But fortunately, the existing half is the part we need, so we don't need to find the missing one," he said, though he added that the condition of the found part remains uncertain.

Earlier, authorities have identified it publically, and possibly mistakenly, as the black box containing the flight data recorder.

According to Haryo Satmiko, the committee's deputy chief, the breaking of the black box "showed how huge the impact was when the plane crashed."

The item arrived at the committee's office about nine hours after it was found and was hustled into a laboratory for inspection.

The twin-engine jetliner crashed into the sea shortly after taking off from Jakarta's Soekarno-Hatta International Airport on Monday morning.

Some body parts have been recovered but no survivors are expected to be found. As of midday Wednesday, only one body had been identified, on the basis of fingerprints.

Soerjanto Tjahjono, the committee's chief, said earlier Thursday that it may take about three weeks to download data from any black boxes recovered. Fact-based preliminary results of the investigation may be released within 30 days, while final draft results are expected within six months, he said.

In a letter sent to the budget airline Thursday, the government ordered the suspension of its director of maintenance and engineering in the wake of the crash of the almost new Boeing 737 MAX 8.

The Transportation Ministry said in a statement that three of Lion Air personnel -- the quality control manager, the fleet maintenance manager and the release engineer -- also had their licenses suspended for 120 days.

The four suspensions came one day after the ministry ordered that of the airline's technical director.

Asked about the possible cause of the crash, Transportation Minister Budi Karya Sumadi said there might be a "mismatch" between the pilot's qualifications and the new type of the plane.

The plane was bound for the island of Bangka, off southeastern Sumatra, when its pilots reported a flight control problem two minutes after takeoff.

Lion Air has acknowledged that the plane had also experienced a technical problem during its previous flight, from Bali to Jakarta on Sunday, though maintaining that it was resolved.

The pilot of the previous flight, according to Haryo, told the transportation safety committee investigators that during its journey from Bali to Jakarta, it ascended and descended several times but managed to land safely.

A U.S. team of investigators including personnel from the National Transportation Safety Board and Boeing Co. arrived in Jakarta on Wednesday.

Since the plane's pilot and co-pilot were experienced -- 6,000 and 5,000 flight hours, respectively -- and weather did not seem to be a major factor, the investigation is expected to focus on the Boeing 737 MAX 8 aircraft. Ten remain in Lion Air's fleet and have been cleared for operation after detailed safety checks.