Passengers lost consciousness up to four hours before the Malaysia Airlines Boeing 777 - dubbed the "ghost plane" disappeared beneath the waves, a veteran New Zealand-based air accident expert said in his report.
The theory, reported in the 'Daily Mirror' newspaper, is the result of the first independent study into the March 8 disaster. Ewan Wilson, the founder of Kiwi Airlines and a commercial pilot himself, has proposed the theory conclusion to investigators after considering "every conceivable alternative scenario".
An earlier report from the Australian Transport Safety Bureau (ATSB) also concluded that passengers may have died from hypoxia and Malaysian authorities had previously named pilot Captain Ahmad Shah as their prime suspect. According to Wilson's research, the most likely scenario is that the pilot deliberately depressurized the cabin, thereby depriving those on board of air.
Although oxygen masks would have dropped down automatically from above the seats, their supply was limited to just 20 minutes. Those unable to grab a mask, including sleeping passengers, would have passed out within the space of a few minutes.
The entire plane, including the cabin crew whose air supply is only marginally longer, would have slipped into a coma and died shortly after from oxygen starvation. Capt Shah, who may have locked his co-pilot out of the cockpit, could have survived long enough either by re-pressurizing the aircraft, or from breathing his own, from a more extensive air supply to evade radar and "execute his master plan", the report said.
He may then have performed a controlled ditching in the sea, which would explain why no debris has been found because the plane landed and sank in one piece, it said. The new theory would put co-pilot Fariq Abdul Hamid in the clear after also being made a suspect in the investigation by Malaysian Police, the report said.