AN OFFICIAL police investigation into the disappearance of Malaysia Airlines flight 370 has identified the captain as the prime suspect — if it is proven human intervention was involved.

Captain Zaharie Shah became the focus of the special investigation in Malaysia after all other passengers were cleared of any suspicious motives, The Sunday Times reported.

After conducting 170 interviews, investigators noted strange behaviour by the pilot.

He had made no future plans - socially or professionally - and his home flight simulator was programmed with a flight path into the depths of the Southern Ocean before landing the plane on an island with a small runway.

The drills were deleted from the computer but specialists were able to retrieve the files.

In the greatest aviation mystery of our time, MH370 vanished without a trace with 239 people on board while en route to Beijing from Kuala Lumpur on March 8 this year.

Although the new conclusion gives insight into the police focus, it does not solve the riddle of the disappearance as the investigation has not ruled out the possibility of terrorism or mechanical failure.

There is also speculation his home life was fraught with difficulties, though this has been denied by his family.

The Sunday Times reported although the results of the inquiry have not been released publicly, they have been shared by those close to the investigation.

Malaysian police said in a statement: “The police investigation is still ongoing. To date no conclusions can be made as to the contributor to the incident and it would be sub judice to say so. Nevertheless, the police are still looking into all possible angles.”

The Malaysian Prime Minister Najib Razak hinted on March 15 the government believed it was possible a “deliberate action by someone on the plane” was behind the MH370 mystery.

Family and friends of Mr Shah claim he was a good man and the truth will be revealed when investigators find the missing black box.