The fuselage of Lion Air flight JT610 may have been located, according to news agency reports.
Reuters and the Associated Press tweeted that the plane had possibly been located on the seabed after crashing on Monday shortly after leaving Jakarta.
The AP reported armed forces chief Hadi Tjahjanto as saying the search and rescue effort had identified the possible seabed location of the jet.
Tjahjanto said a team would be sent to the identified location to confirm the findings.
Searchers had previously found the debris field left floating on the surface when the jet plunged into the sea and some human remains but not the fuselage.
A high priority will be retrieving the aircraft’s “black boxes” – the flight data and cockpit voice recorders – likely to give investigators crucial information on factors contributing to the crash.
The Boeing 737 MAX 8 crashed on Monday with 189 people on board just 13 minutes after take-off from Jakarta airport at 6:21am local time.
The recently-delivered plane had just 800 flight hours on the clock and a preliminary analysis by flight tracking websites showed erratic altitude and speed data before the aircraft plunged into the water at high speed.
READ Indonesia orders inspections of all 737 MAX 8s.
The accident is the first involving the 737 MAX 8, a new version of Boeing’s venerable workhorse that delivers greater efficiency and other high-tech enhancements.
Indonesian transportation officials ordered inspections of other MAX 8 aircraft but said they would not be grounded despite the issues raised by the crash and a flight the previous day that also had technical problems.
An Indonesian official confirmed the problem with the Sunday flight included unreliable airspeed indications.
There is no way of knowing at this stage what caused the crash but speculation has included problems related to the pitot tubes, which measure kinetic and static air pressure to provide crucial information such as airspeed, and issues with the elevators.
READ New theory in Lion Air disaster.
Other concerns raised by commentators include pilot training and the ability of flight crew to deal with unexpected events.
Indonesia is leading the investigation the US National Transportation Safety Board (NTSB) will be party to it and technical advisers from Boeing and engine maker CFM International will also be involved.
Boeing said in a short statement that it was providing technical assistance under the direction of investigating authorities.
