The government’s chief investigator concluded that the Boeing 777 lost contact with air traffic control after being manually re-directed after take-off.
Kok Soo Chon said: “What we have established is that the aircraft has turned back. We can conclude that MH370 had turned back and the turn back was not because of anomalies in the mechanical system. The turn back was made not under autopilot but under manual control.”
Mr Chon added that there was no evidence to support the theory that the plan was taken over remotely by hackers.
He added: “We cannot exclude the possibility that there was unlawful interference by a third party.”
The report comes two months after Malaysia called off a privately funded underwater search for the aircraft carrying 239 people that disappeared on its way to Beijing from Kuala Lumpur on March 8, 2014, in one of the world’s greatest aviation mysteries.
Mr Chon could not explain if the the final two turns over the south of Penang and the north of Mekar were under control or on autopilot.
He said: “The radio and telephone communication by the pilot and first officer with the controllers show there was no evidence of any anxiety or stress.
“The aircraft maintainers record indicates the aircraft was well maintained. There was no record of any malfunction or defect of the aircraft — none that could have contributed to the disappearance.
“It is possible that the absence of communications prior to flight path diversion was due to the systems being manually turned off, whether with intent or otherwise the route followed by the aircraft, the height at which it flew, did not suggest any mechanical problem with the aircraft’s control system, fuel or engines.
“The lack of evidence includes the information recorded on the fly data recorder, and other recording devices on the aircraft that could indicate why is aircraft had flown to the southern Indian Ocean. In conclusion, the team is unable to determine the real cause for the disappearance of MH-370.”