KUALA LUMPUR - The youngest son of the pilot whose flight went down in the Indian Ocean has dismissed speculation that his father may have crashed the plane intentionally.

Mr Ahmad Seth, son of captain Zaharie Ahmad Shah, said he knew what kind of man his father was, New Straits Times (NST) reported on Thursday.

"I've read everything online. But I've ignored all the speculation. I know my father better," the 26-year-old was quoted as saying.

"We may not be close as he travels so much. But I understand him," the language student told the newspaper in his first public remarks since flight MH370 disappeared on March 8 while travelling from Kuala Lumpur to Beijing.

Mr Seth appeared calm and composed during the interview, and did not reveal any resentment against those who portrayed his father as a "hijacker", according to the newspaper.

His mother Faizah Khanum Mustafa Khan, elder siblings Ahmad Idris and Aishah, have thus far not spoken to the media, said the report.

Mr Seth said he was not surprised by Prime Minister Najib Razak's announcement that the plane had gone down in the Indian Ocean.

In a resigned tone, he said he had expected the outcome after having waited for 18 days for news on the aircraft and its 239 passengers and crew members. Nevertheless, he was still clinging on to a glimmer of hope.

"Now, we are just waiting for the right confirmation (for the wreckage or bodies).

"I will believe it (that there are no survivors) when I see the proof in front of my eyes," he told NST.

His friends, he said, had been a pillar of strength and lent him their support and encouragement. He also reluctantly admitted that he was the strongest in his family in dealing with the crisis, but did not elaborate on how his other family members were coping, said the report.

Mr Zaharie, 53, along with his co-pilot Fariq Abdul Hamid, 27, has come under intense scrutiny after Malaysian authorities said flight MH370's disappearance was due to "deliberate" action by someone on the plane.

Malaysian police have already questioned the family members of the pilots and other crew and seized a home-built flight simulator which Mr Zaharie installed in his house.

But they have not announced finding any evidence against him.

The US Federal Bureau of Investigation will complete its analysis of data deleted from the flight simulator "within a day or two", its director said on Wednesday in Washington.

Malaysian officials had asked the FBI to help recover files deleted from the simulator's hard drive. FBI chief James Comey did not indicate whether the results of the analysis would be made public.