Captain Zaharie Shah had no social or professional engagements after March 8, the day the flight disappeared with 239 passengers and crew on board.
While the Malaysian police investigation has not ruled out mechanical failure as an explanation, Captain Shah is said to be the most likely culprit if human action was to blame.
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Sakinab Ahmad Shah maintains her brother's innocence
But Captain’s Shah’s sister Sakinab Ahmad Shah has dismissed the notion her brother was responsible.
She said: “We couldn’t figure out why somebody who would want to commit suicide would prolong the agony of flying for four, five, six hours just to land down there.
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A photo of Zaharie Shah (top right) and co-pilot Fariq Abdul Hamid (top left) atop a poster appealing for the missing plane to 'please come back'
“If it was done, if he was the one who planned it, he has to be some kind of Einstein, which he was not.”
The Boeing 777 is believed to have crashed in the southern Indian Ocean, but not a single piece of debris has been identified in an extensive search involving more than a dozen countries.
A relative of passengers onboard the Malaysia Airlines Flight MH370, waits for a briefing
But Shah is standing by her brother, adding: “He was just a man who took so much to aviation. He loved aviation, he spent a lot of his funds buying model airplanes.
“If he could, I think he would attach wings to himself and fly – he loved flying that much.”
Family members of passengers are seeking to raise $5 million for a reward and private investigation leading to discovery of what happened to the missing jet, in the hope whistleblowers will come forward.
Search For MH370
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A Chinese relative of passengers on the missing Malaysia Airlines flight MH370 uses a lighter as she prays at the Metro Park Hotel in Beijing on April 8, 2014. The hunt for physical evidence that the Malaysia Airlines jet crashed in the Indian Ocean more than three weeks ago has turned up nothing, despite a massive operation involving seven countries and repeated sightings of suspected debris. AFP PHOTO/WANG ZHAO (Photo credit should read WANG ZHAO/AFP/Getty Images) (credit:Getty Images)
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Chinese relatives of passengers on the missing Malaysia Airlines flight MH370 take part in a prayer service at the Metro Park Hotel in Beijing on April 8, 2014. The hunt for physical evidence that the Malaysia Airlines jet crashed in the Indian Ocean more than three weeks ago has turned up nothing, despite a massive operation involving seven countries and repeated sightings of suspected debris. AFP PHOTO / WANG ZHAO (Photo credit should read WANG ZHAO/AFP/Getty Images) (credit:Getty Images)
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Chinese relatives of passengers on the missing Malaysia Airlines flight MH370 take part in a prayer service at the Metro Park Hotel in Beijing on April 8, 2014. The hunt for physical evidence that the Malaysia Airlines jet crashed in the Indian Ocean more than three weeks ago has turned up nothing, despite a massive operation involving seven countries and repeated sightings of suspected debris. AFP PHOTO / WANG ZHAO (Photo credit should read WANG ZHAO/AFP/Getty Images) (credit:Getty Images)
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A woman reacts as Chinese relatives of passengers on the missing Malaysia Airlines flight MH370 take part in a prayer service at the Metro Park Hotel in Beijing on April 8, 2014. The hunt for physical evidence that the Malaysia Airlines jet crashed in the Indian Ocean more than three weeks ago has turned up nothing, despite a massive operation involving seven countries and repeated sightings of suspected debris. AFP PHOTO / WANG ZHAO (Photo credit should read WANG ZHAO/AFP/Getty Images) (credit:Getty Images)
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Chinese relatives of passengers on the missing Malaysia Airlines flight MH370 take part in a prayer service at the Metro Park Hotel in Beijing on April 8, 2014. The hunt for physical evidence that the Malaysia Airlines jet crashed in the Indian Ocean more than three weeks ago has turned up nothing, despite a massive operation involving seven countries and repeated sightings of suspected debris. AFP PHOTO / WANG ZHAO (Photo credit should read WANG ZHAO/AFP/Getty Images) (credit:Getty Images)
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A woman lights a candle as Chinese relatives of passengers on the missing Malaysia Airlines flight MH370 take part in a prayer service at the Metro Park Hotel in Beijing on April 8, 2014. The hunt for physical evidence that the Malaysia Airlines jet crashed in the Indian Ocean more than three weeks ago has turned up nothing, despite a massive operation involving seven countries and repeated sightings of suspected debris. AFP PHOTO / WANG ZHAO (Photo credit should read WANG ZHAO/AFP/Getty Images) (credit:Getty Images)
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PERTH, AUSTRALIA - APRIL 08: Air Chief Marshal Angus Houston (Ret'd) and Defence Minister David Johnston address the media during a press conference over the continuing search for missing Malaysia Airlines Flight MH370 at RAAF Base Pearce on April 8, 2014 in Perth, Australia. ACM Angus Houston advised the towed pinger by ADV Ocean Shield is still trying to re-locate the signals previously detected, which were believed to be consistent with aircraft black boxes. The airliner disappeared on March 8 with 239 passengers and crew on board and is suspected to have crashed into the southern Indian Ocean. (Photo by Paul Kane/Getty Images) (credit:Getty Images)
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PERTH, AUSTRALIA - APRIL 07: A US Navy Poseidon P-8 takes off to assist in the search for debris from missing Malaysia Airlines Flight MH370 at Perth International airport on April 7, 2014 in Perth, Australia. Angus Houston confirmed today that the Australian naval vessel Ocean Shield has twice detected signals in the past 24 hours consitent with aircraft black boxes. The airliner disappeared on March 8 with 239 passengers and crew on board and is suspected to have crashed into the southern Indian Ocean. (Photo by Paul Kane/Getty Images) (credit:Getty Images)
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Angus Houston, head of the Joint Agency Coordination Centre leading the search for missing Malaysia Airlines flight MH370, points to a graphic of the search area during a media conference in Perth on April 7, 2014. An Australian navy ship has detected new underwater signals consistent with aircraft black boxes, Houston said on April 7, describing it as the 'most promising lead' so far in the month-old hunt for missing Flight MH370. AFP PHOTO / Greg WOOD (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:Getty Images)
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PERTH, AUSTRALIA - APRIL 07: Air Chief Marshal Angus Houston (ret'd) holds a map outlining the current search areas of naval ships Ocean Shield and Haixun 01 during a press conference for the continuing search of missing Malaysia Airlines Flight MH370 at Dumas House on April 7, 2014 in Perth, Australia. Angus Houston confirmed today that the Australian naval vessel Ocean Shield has twice detected signals in the past 24 hours consitent with aircraft black boxes. The airliner disappeared on March 8 with 239 passengers and crew on board and is suspected to have crashed into the southern Indian Ocean. (Photo by Paul Kane/Getty Images) (credit:Getty Images)
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Malaysian Buddhists offer prayers for passengers onboard missing Malaysia Airlines (MAS) flight MH370 in Kuala Lumpur on April 6, 2014. A Chinese ship searching the Indian Ocean for flight MH370 detected a signal at a frequency used by the missing aircraft's black boxes on April 5, but Australia warned there was no evidence yet that it was linked to the plane. AFP PHOTO / MOHD RASFAN (Photo credit should read MOHD RASFAN/AFP/Getty Images) (credit:Getty Images)
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An Australian Air Force Orion takes off from Pearce Airbase in Bullsbrook, 35 km north of Perth, to join the hunt for a missing Malaysia Airlines plane in the Indian Ocean on April 6, 2014. Planes and ships were being diverted on April 6 to the area where a Chinese vessel detected signals consistent with a black box beacon in the hunt for missing Malaysia Airlines flight MH370, the search chief said. AFP PHOTO / Tony ASHBY (Photo credit should read TONY ASHBY/AFP/Getty Images) (credit:Getty Images)