President Joko Widodo visited the command centre at Jakarta's international container terminal where tonnes of plane debris hauled by divers from seafloor were collected for an investigation into what caused the Boeing 737-500 to nosedive into the Java Sea shortly after take-off from Jakarta on January 9.

He also witnessed the first three relatives of the victims receiving money from the compensation fund.

Sriwijaya Air offered relatives an insurance payout of 1.25 billion rupiah ($A115,320), in line with the Indonesian law that stipulates compensation must be offered within 60 days of a crash.

In addition, state-owned insurance company Jasa Raharja has provided 50 million rupiah to each family of the victims.

"I assure you that all compensation will be completed immediately for all victims," Widodo said.

A search is still ongoing for the crucial memory unit of the cockpit voice recorder.

The device apparently broke loose from its exterior and officials have said the underwater locator beacons attached to both crash-proof black boxes became dislodged due to the impact.

The flight data recorder was recovered three days after the crash.

Australian Associated Press