MH370: "We may not even know the real cause for the disappearance" - IGP

Inspector-General of Police Tan Sri Khalid Abu Bakar said the investigation has now been classified as a criminal investigation focused on four areas – hijacking, sabotage and personal or psychological problems of those on board the plane.

"Investigations may go on and on and on. We have to clear every little thing," Khalid said. "At the end of the investigations, we may not even know the real cause. We may not even know the reason for this incident," he said.

Khalid said that so far the police had recorded statements from more than 170 individuals over the disappearance of the Boeing 777-200 aircraft, and added that they would record many more statements.

According to the Associated Press, police have “cleared” all passengers on board flight MH370 of the four areas of investigation and is now focusing on the cabin crew including the pilot and co-pilot.

"They have been cleared of the four (elements). It (is) according to our own procedure (investigation)," he told reporters after opening a quality-enhancing seminar for the police here today.

He added that the investigation into the flight simulator in the pilot’s house in still inconclusive and authorities are awaiting an expert’s report on the simulator.

“We must be very thorough and we need all the time… you cannot hurry us,” he said.

Police are also investigating the cargo and even the food served on the plane to eliminate possible sabotage, he added.

Flight MH370, carrying 227 passengers and 12 crew members left KL International Airport at 12.41am on March 8 and disappeared from radar screens about an hour later while over the South China Sea. It was to have landed in Beijing at 6.30am on the same day.

Chinese relatives of the passengers have been critical of the handling of the search for the plane, especially as the focus of the hunt has shifted. After experts analyzed the limited radar and satellite data from the plane, the search area was moved from the seas off Vietnam, to several areas in the Indian Ocean west of Australia and finally to a 221,000 square kilometre area, about 1,450 kilometers from Perth. Prime Minister Datuk Seri Najib Tun Razak announced on March 24, seventeen days after the disappearance of the Boeing 777-200 aircraft, that Flight MH370 "ended in the southern Indian Ocean".

Khalid said the police would not release any findings of the investigation into the incident as it would jeopardise the ongoing probe.

"I'm sorry, there are things we cannot reveal to you; not that I don't want to reveal to you but we cannot do that. Because it's a criminal investigation, ongoing; we have not concluded the whole thing and we are still awaiting reports from experts overseas and internally.