US investigators suspect that Malaysia Airlines Flight 370 stayed in the air for about four hours past the time it reached its last confirmed location, the Wall Street Journal reported, citing two people familiar with the details.

The report comes as authorities remain uncertain about which ocean to search for the jetliner that went missing on Saturday after taking off from Kuala Lumpur. The latest disclosure led US investigators to explore the possibility that someone deliberately turned off the transponder and diverted the plane to another location, the newspaper reported.

It raises the possibility that the plane, and the 239 people on board, could have flown on for additional distance of about 2,200 miles (3,500 km), potentially reaching the border of Pakistan or as far as destinations in the Indian Ocean or Arabian Sea, the paper said.

The last definitive sighting of the aircraft on civilian radar screens came shortly before 1:30 a.m. on Saturday, less than an hour after taking off from Kuala Lumpur, as it flew northeast across the mouth of the Gulf of Thailand bound for Beijing.

Please LIKE our Facebook page - it makes us stronger