Malaysia Plane Probe Focuses On Crew And Pilots

A Royal Navy submarine has joined the search for flight MH370 in the Indian Ocean - as Malaysia's police chief said the investigation was focusing on the pilots and cabin crew.

Khalid Abu Bakar said criminal investigations were continuing to focus on four possibilities: hijacking, sabotage and personal or psychological problems of those on board.

He said all 227 passengers had been "cleared" of any possible involvement.

Though authorities had not ruled out the possibility the jet may have suffered mechanical problems, the evidence suggested the aircraft was deliberately diverted from its planned flight path, he said.

Mr Bakar also warned the cause of the tragedy may never come to light.

"We have to clear every little thing," he 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."

The cargo and the food served on the plane are also being looked at to eliminate possible sabotage, he added.

As the clock counts down on the battery life of the black box's locator beacon, the search has been bolstered by British submarine HMS Tireless, which has now arrived in the Indian Ocean.

The Trafalgar Class submarine is expected to try to detect the all-important device, which could hold the key to unravelling the mystery.

Royal Navy survey ship HMS Echo is also due to join the international search operation later. Nine planes and nine other ships are also still involved in the hunt 930 miles west of Perth, Western Australia.

A defence source said: "A Royal Navy Trafalgar Class submarine has recently arrived in the area and is conducting search operations for the flight recorders.

"HMS Tireless holds advanced search capabilities, but the task in hand remains a tall order and the search area is immense."

Flight MH370 went missing on March 8 with 239 people on board. The aircraft took off from Kuala Lumpur International Airport, bound for Beijing.

The three-week search operation has repeatedly shifted its focus as experts analyse radar and satellite data on the plane's movements.

Relatives of the passengers were meeting airline and Malaysian government representatives at a closed-doors meeting in Kuala Lumpur on Wednesday.

Family members have repeatedly accused the authorities of lying to them and holding back information.

Multiple sightings of possible debris have so far failed to turn up any sign of the aircraft, which investigators say - beyond reasonable doubt - went down in the Indian Ocean.

Australian Prime Minister Tony Abbott called the disappearance "one of the great mysteries of our time" and again promised to continue the hunt for as long as needed.

The Australian premier is also set to meet Malaysian Prime Minister Najib Razak in Perth later.

"We owe it to the world, we owe it to those families to do whatever we reasonably can get to the bottom of this," Mr Abbot said.