The head of the National Transportation Safety Committee, Soerjanto Tjahjono, says pings detected at sea in the search for a crashed Lion Air plane are definitely from its flight recorder due to their regular pattern.
It was orange in colour and intact, he said, without saying whether it was the flight data recorder or the cockpit voice recorder, which are both usually referred to as black boxes.
With media speculating on the airworthiness of the aircraft, the transport ministry suspended for 120 days Lion Air's maintenance and engineering director, fleet maintenance manager and the release engineer who gave the jet permission to fly on Monday.
Budi Karya Sumadi added that President Joko Widodo had ordered a review of all flight safety regulations after this week's crash of a jet operated by budget carrier Lion Air with 189 aboard.
"An RTB was requested and had been approved but we're still trying to figure out the reason", Tjahjono told reporters on Monday.
Officers at Jakarta's port picked through personal belongings retrieved from the sea, including wallets, backpacks and papers, in a bid to help identify their owners.
Authorities said Wednesday they believed they had pinpointed the resting place of the Lion Air jetliner, which vanished from radar screens after taking off on a flight to nearby Bangka-Belitung island.
The flight data recorder contains technical information about the flight, detailed by the plane's onboard flight systems.
Indonesia's disaster agency posted photos online of a crushed smartphone, books, bags and parts of the aircraft fuselage that had been collected by search and rescue vessels that have converged on the area.
Rescuers have also located a 70-foot-long object on the seafloor that they believe is the plane's fuselage and are working to confirm the origin of an underwater "ping" thought to have come from one of the plane's recorders, Reuters reports.
The cause of the crash has yet to be established, but questions have been raised after Lion Air admitted the plane had an unspecified technical issue on a previous flight.
The crew received the green light to turn around, but lost altitude and crashed into the sea less than 15 minutes into the flight. This saw Indonesian airlines temporarily banned from flying to European countries.