PETALING JAYA, March 8 — Two years after the mysterious disappearance of MH370, Capt Zaharie Ahmad Shah is again under the spotlight, with the “rogue pilot” speculation gaining traction as other theories fizzle out.

Fueled in part by a picture which surfaced on the internet of Zaharie sitting in front of a flight simulator he had built in his house in Shah Alam, the theory was one of the earliest to be bandied about as the world searched for answers.

One of the main proponents of the theory is Australian airline captain Byron Bailey.

He said in a report in The Australian last Friday that the Australian Transport Safety Bureau (ATSB), which is leading the search for the missing Boeing 777, had wasted two years looking in the wrong places by relying on a “nonsensical end-of-flight theory”.

“Why didn’t the ATSB consider the obvious rogue pilot theory? Not even after the head of Emirates — the largest B777 operator and my former boss — stated on live television that MH370 was flown under control for 7½ hours and that pilots should not be able to turn off communication and tracking equipment in flight.

“Why didn’t the ATSB take note of this very important statement?,” he said in the report, referring to Emirates Airlines president Sir Tim Clark’s comments in October 2014.

Clark had said he did not believe the flight was on autopilot when it disappeared, claiming: “MH370 was, in my opinion, under control, probably until the very end”.

While dismissing the rogue pilot theory, ATSB chief commissioner Martin Dolan said the lack of results was forcing searchers to reconsider their “ghost flight” theory.

“The search effort is based on a hypothesis that MH370, became a ‘ghost flight’ ... that the aircraft continued travelling on autopilot and crashed when it ran out of fuel.

“This is supported by analysis of satellite data that the plane continued to fly for more than six hours after contact was lost,” he said.

ATSB believes MH370 had flown on autopilot before it ended up in the Southern Indian Ocean. The theory is that an event on the plane could have rendered its passengers and crew unconscious.

In February, Dolan told The Times they were willing to consider the “rogue pilot theory”.

“We are not at the point yet, but sooner or later we will be and we will have to explain to governments what the alternative is,” Dolan was then reported as saying.

“The alternative is, frankly, despite all the evidence we currently have on the possibility that someone was at the controls of that aircraft and gliding it, becomes a more significant possibility if we eliminate all of the current search area.

“In a few months' time, if we haven’t found it, then we will have to be contemplating that one of the much less likely scenarios ends up being more prominent. Which is that there were control inputs into that aircraft at the end of its flight.”

Malaysian police had looked into the theory early into their investigations.

Inspector-General of Police Tan Sri Khalid Abu Bakar had, on April 2, 2014, said they were investigating the case from four angles, namely personal and psychological problems, sabotage and hijacking.

While he confirmed Zaharie's simulator was also examined, police had found nothing to prove the pilot, who joined Malaysia Airlines in 1981, had gone rogue.

Nonetheless, proponents of the rogue pilot theory also claimed Zaharie was a strong supporter of opposition leader Datuk Seri Anwar Ibrahim and that he was a distant relative of Anwar's daughter-in-law.

The incident had happened a day after Anwar was sentenced to five years’ jail on sodomy charges.

Anwar's daughter Nurul Izzah said in an interview by Xinhua earlier this month the link between them was just coincidental.

Zaharie's family had also repeatedly denied any domestic problems, maintaining he was a professional and responsible employee of the airline.

In an interview by AP on March 2, Zaharie's sister Sakinab Shah said her younger brother was being made a scapegoat.

“When the search revealed nothing, they came back to this theory, but it is only a theory,” she said in the interview.

“If you have nothing tangible and nothing by way of evidence, it is tantamount to predicting he is guilty until proven innocent. This sets us back to the Dark Ages.

“Please do not judge him based on theories. Don't blame him unless there is evidence.

“He is innocent until proven guilty. That is the mantra of modern civilisation.”