By Tim Hepher and Jane Wardell KUALA LUMPUR/SYDNEY (Reuters) - Australia will lead a search of the remote southern Indian Ocean for a missing Malaysian jet liner, its prime minister said on Monday, amid mounting evidence the plane's disappearance was a meticulously planned act of sabotage or hijacking. No trace of Malaysia Airlines Flight MH370 has been found since it vanished on March 8 with 239 people aboard. Investigators are increasingly convinced it was diverted perhaps thousands of miles off course by someone with deep knowledge of the Boeing 777-200ER and commercial navigation. But police and a multi-national investigation team may never know for sure what happened aboard the jetliner unless they find the plane, and that in itself is a daunting challenge.
An investigation into the pilots of missing Malaysia Airlines Flight 370 intensified Monday after officials confirmed that the last words spoken from the cockpit came after a key signalling system was manually disabled. US intelligence efforts were also focusing on Captain Zaharie Ahmad Shah and his first officer, Fariq Abdul Hamid, according to a senior US lawmaker. "I think from all the information I've been briefed on from, you know, high levels within homeland security, national counterterrorism centre, intelligence community, that something was going on with the pilot," said Michael McCaul, the chairman of the House Homeland Security Committee. Malaysia's transport minister confirmed Sunday that an apparently relaxed final voice communication from the cockpit -- "All right, good night" -- came after the Aircraft Communications Addressing and Reporting System (ACARS) had been deliberately shut down.