Malaysian authorities have started examining the personal flight simulator owned by one of the pilots of a missing Boeing 777.

The announcement came as authorities said the search for the disappeared jet now spanned an area including 11 countries from central Asia to the Indian Ocean with help from 25 countries - up from 14.

"The search was already a highly complex, multinational effort. It has now become even more difficult," said acting Malaysian Transport Minister Hishammuddin Hussein.

Authorities were still digging through the background of the 239 people on board and ground crew but the wild speculation surrounding the plane's disappearance has swung back to pilot Zaharie Ahmad Shah.

Newspapers have branded him a "fanatical" supporter of opposition leader Anwar Ibrahim, who campaigns for greater democracy and against corruption and ethnic discrimination.

Why support for Mr Ibrahim would lead someone to hijack an aeroplane was unclear.

Officials revealed that the final words from the cockpit as communications were being disabled were: "All right, good night."

Not reporting any problems lead to speculations that the pilots may have been misleading ground control staff.

"This is something not normal that the pilot would do," said Major General Affendi Buang.

But it was not actually clear which of the two pilots said the words, or indeed if it was someone else.

Mr Hishammuddin said he had asked governments to hand over sensitive radar and satellite data to try and help get a better idea of the plane's final movements.