A missing airliner appears to have been deliberately steered off course after someone on board shut down its communications, Malaysia’s Prime Minister Najib Razak said yesterday.

A week after the disappearance of flight MH370, Najib said its last transmission of satellite data came nearly seven hours after it disappeared from radar screens.

But the new data gave no precise location and the altered course could have taken it anywhere from central Asia to the southern Indian Ocean, he said.

Minutes after the Malaysian leader outlined investigators’ latest findings, police began searching the house of the aircraft’s 53-year-old captain for any evidence that he could have been involved in foul play.

The Malaysia Airlines Boeing 777-200ER vanished en route from Kuala Lumpur to Beijing in the early hours of March 8 with 239 passengers and crew aboard.

Najib, giving his first statement at a news conference since then, confirmed reports that investigators believe somebody cut off the plane’s communications reporting system, switched off its transponder and steered it west, far from its scheduled route.

“In view of this latest development the Malaysian authorities have refocused their investigation into the crew and passengers on board,” he said.

Search operations by navies and aircraft from more than a dozen nations were immediately called off in the Gulf of Thailand and the South China Sea, where the plane dropped off civilian air traffic control screens at 1.22am.

Malaysia said data showed the last communication between the missing plane and satellites at 8.11am, almost seven hours after it turned back and crossed the Malay peninsula.

Najib said the plane’s final communication with satellites placed it somewhere in one of two corridors: a northern arc stretching from northern Thailand to the border of Kazakhstan and Turkmenistan, or a southern one stretching from Indonesia to the vast southern Indian Ocean.