Malaysia is focusing its criminal investigation on the cabin crew and pilots of a missing Malaysia Airlines plane, after clearing all 227 passengers of any involvement.
National police chief Khalid Abu Bakar said on Wednesday that passengers had been cleared of possible involvement in hijacking, sabotage or having personal or psychological problems that could have been connected to the flight's disappearance on 8 March.
Authorities have still not ruled out mechanical problems as causing Flight MH370 to vanish, but say evidence suggests it was deliberately diverted from its scheduled route from Kuala Lumpur to Beijing.
Investigators believe that someone with detailed knowledge of the Boeing 777-200ER and commercial aviation navigation switched off the plane's communications systems before diverting it thousands of kilometres off its scheduled course, Reuters reports.
That has turned the focus of investigations onto the pilots - captain Zaharie Ahmad Shah, 53, and his co-pilot, 27-year-old Fariq Abdul Hamid.
However, police say their investigation into the men has failed to turn up any red flags. The FBI helped Malaysian authorities analyse data from Captain Zaharie's personal flight simulator but found nothing suspicious.
Race to find black box
The search for the missing airliner resumed on on Wednesday, amid concerns that bad weather and a lack of reliable information are seriously impeding the operation.
Up to 10 planes and nine ships are scouring a stretch of the southern Indian Ocean where the plane is believed to have crashed.
Search teams in the southern Indian Ocean are in a race against time to locate the plane's black box recorder, which has an expected battery life of about 30 days and may well contain the key to understanding the plane's mysterious disappearance.
"We are focusing on the pilots but we can't get much clarity until we have the black box," one senior police source told Reuters.
No objects pulled from the sea have been identified as being from the airliner and the search could drag on for weeks or possibly months.
Malaysian Prime Minister Najib Razak is expected in Perth on Wednesday to inspect the search and rescue operations.
Cockpit transcripts released
Malaysia has released a transcript of communications between the cockpit crew of Flight MH370 and air traffic controllers, saying the exchanges show nothing untoward.
The 43 separate transmissions over nearly 54 minutes from the plane are thick with air traffic and navigational jargon and give no hint of trouble aboard the plane, AFP reports.
The transcript concludes with Malaysian air traffic control first bidding MH370 "good night", as it instructs the pilots next to contact controllers in Vietnam, over which the plane was due to fly.
The final entry from just after 1.19am on 8 March came from one of the pilots who said "good night, Malaysian three seven zero". The plane disappeared from radar shortly thereafter.
The transcript - and particularly the final words from MH370 - have been the subject of much speculation following earlier statements that the last transmission from the plane was a casual "All right, good night".
