Malaysian police are investigating the likelihood that the veteran captain of doomed Malaysia Airlines Flight 370 was the prime suspect in the disappearance of the jet that was carrying 238 people, reports the Sunday Times.

The flight went off radar on March 8 on a routine flight from Kuala Lumpur to Beijing, and while officials are not ruling out terrorism or mechanical failure, Captain Zaharie Shah – who joined the airline in 1981 – is now the most likely suspect.

Malaysian police conducted more than 170 interviews and found that Shah, 53, had made no commitments for after the flight, which is typically unlike the “jovial, outgoing, married man with a penchant for gadgetry and postings on social media,” according to the Sunday Times.

“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,” a Malaysian police spokesman said to the Sunday Times. 

The family has denied the rumors that Shah was having marital problems. But the police found that Shah had “programmed a flight simulator at home to practice a flight far out at sea in the Indian Ocean and landing on an island with a short runway,” reported the New York Daily News. Police found that the simulator was deleted from the computer Feb. 3.

It has been more than 100 days since the Malaysian plane last had any contact with radar, but investigators are preparing for another search in August in the Indian Ocean. In the early days after the plane disappeared, questions were raised about whether MH370's disappearance was a case of pilot suicide