A US official has revealed that investigators are looking into the possibility that the "conclusive" hijacking of missing Malaysia Airlines flight MH370 may have been "an act of piracy" as conflicting reports emerge.
Pilot suicide is another motive that investigators are studying as the route of the aircraft, a sharp turn westwards towards the Indian Ocean, becomes more conclusive.
Within a few hours of reports that the Boeing 777 was hijacked, the chief of the investigation has said the reports are "not true".
"It is not conclusive. I'm heading the investigation and nobody is saying that. It's not true. We are looking at the possibility, we're looking at all possibilities," Malaysia's civil aviation chief Azharuddin Abdul Rahman, who is leading the entire investigation, told the Telegraph.
"We're doing every profile of the passengers and crew but there is no firm evidence or leads so far," he said.
However, electronic signals sent to satellites from the missing Malaysia Airlines flight MH370 shows that it may have flown thousands of miles before running out of fuel and crashing into the Indian Ocean, according to a US official.
The source, familiar with official US assessments, said that analysis of the satellite signals is allowing investigators to narrow their theories as to what happened on flight MH370, of which 239 people were on board.
A Malaysian government official has revealed that investigators in the search for missing Malaysian Airlines flight MH370 have come to the conclusion that the airliner was hijacked.
The official said that the hijacking of the missing flight was no longer a theory, "it is conclusive", according to the Associated Press.
"It has to be a skilled, competent and a current pilot. He knew how to avoid the civilian radar. He appears to have studied how to avoid it," the military official said.
It remains unclear where the airliner was taken hostage and no motive has yet been established for the hijacking.
Malaysian authorities and international authorities are investigating the psychological, criminal and general backgrounds of the two pilots and 10 crew members, as well the 227 passengers on board in search of potential motives.
The official declared that the investigators understand that one of the pilots or someone with substantial flying experience hijacked the missing jet.
New evidence has indicated that the transponder of the missing Malaysia Airlines flight MH370 was shut down deliberately rather than as a result of a catastrophic failure, with officials citing sabotage and hijacking.
Officials also believe the airliner was being flown towards the Andaman Islands, an archipelago between the Andaman Sea and the Bay of Bengal.
Two sources told Reuters that military radar plotted the airliner off Malaysia's northwest coast. The last plot recorded on the aircraft suggested that its flight path was headed toward the Andaman Islands.
A third source told Reuters that the investigation was focusing increasingly on the theory that someone who knew how to fly a plane deliberately diverted the flight.
"What we can say is we are looking at sabotage, with hijack still on the cards," said the source, a senior Malaysian police official.
When asked about the possibility of the aircraft being flown towards the archipelago at a press conference, Malaysian Transport Minister Hishammuddin Hussein was coy in his answer.
"We don't release information unless it has been corroborated. We don't comment on unnamed sources," he said.
When asked, Hussein did not deny the possibility of a hijacking.
"I cannot confirm whether there is no hijacking. We are looking at all possibilities," he continued.
FLIGHT MH370 FACTBOX
Flight MH370 took off from Kuala Lumpur International Airport en route to Beijing at 00:41 on Saturday 8 March (16:41 GMT Friday).
About 50 minutes later, the aircraft lost contact with air traffic control.
No distress call was made.
On board, there were 12 Malaysian crew members and 227 passengers from 14 countries. That included 153 Chinese and 38 Malaysians.
Two Iranian male passengers, Pouria Nour Mohammad Mahread and Delavar Syed Mohammad Reza, were travelling on fake passports. Neither had any apparent links to terrorist groups.
No debris from the plane has been found in the international search.
At least 10 countries, including China, the US and Singapore, were using a total of 42 ships and 39 aircraft to search for the missing plane in the South China Sea, the Malacca Strait and the Andaman Sea.