Malaysia's military believes it tracked a missing jetliner by radar over the Strait of Malacca, far from where it last made contact with civilian air traffic control off the country's east coast, a military source told Reuters.
In one of the most baffling mysteries in recent aviation history, a massive search operation for the Malaysia Airlines Boeing 777-200ER, now in its fourth day, has so far found no trace of the aircraft or the 239 passengers and crew.
"It changed course after Kota Bharu and took a lower altitude. It made it into the Malacca Strait," the military official, who has been briefed on investigations, told Reuters.
The Strait of Malacca, one of the world's busiest shipping channels, runs along Malaysia's west coast. The airline said on Saturday that radio and radar contact with Flight MH370 was lost off the east coast Malaysian town of Kota Bharu.
Police had earlier said they were investigating whether any passengers or crew on the plane had personal or psychological problems that might explain its disappearance, along with the possibility of a hijack, sabotage or mechanical failure.
The plane left Kuala Lumpur for Beijing early on Saturday morning, vanishing from civilian radar screens about an hour after take-off over the sea separating eastern Malaysia from the southern tip of Vietnam.
There was no distress signal or radio contact indicating a problem and, in the absence of any wreckage or flight data, police have been left trawling through passenger and crew lists for potential leads.
"Maybe somebody on the flight has bought a huge sum of insurance, who wants family to gain from it or somebody who has owed somebody so much money, you know, we are looking at all possibilities," Malaysian police chief Khalid Abu Bakar told a news conference.
"We are looking very closely at the video footage taken at the KLIA (Kuala Lumpur International Airport), we are studying the behavioural pattern of all the passengers."
The fact that at least two passengers on board had used stolen passports, confirmed by Interpol, has raised suspicions of foul play. But Southeast Asia is known as a hub for false documents that are also used by smugglers, illegal migrants and asylum seekers.
Police chief Khalid said one of the men had been identified as a 19-year-old Iranian, Pouria Nour Mohammad Mehrdad, who appeared to be an illegal immigrant. The identity of the other was still being checked.
"We believe he is not likely to be a member of any terrorist group, and we believe he was trying to migrate to Germany," Khalid said of the teenager. His mother was waiting for him in Frankfurt and had been in contact with authorities, he said.
Asked if that meant he ruled out a hijack, Khalid said: "(We are giving) same weightage to all (possibilities) until we complete our investigations."
Both men entered Malaysia on Feb 28, at least one from Phuket, in Thailand, eight days before boarding the flight to Beijing, Malaysian immigration chief Aloyah Mamat told the news conference. Both held onward reservations to Western Europe.
Police in Thailand, where the passports were stolen and the tickets used by the two men were booked, said they did not think they were linked to the disappearance of the plane.
"We haven't ruled it out, but the weight of evidence we're getting swings against the idea that these men are or were involved in terrorism," Supachai Puikaewcome, chief of police in the Thai resort city of Pattaya, told Reuters.