KUALA LUMPUR - As the world scrambles to solve the frustrating puzzle of the missing Malaysia Airlines flight MH370, every possible motive is being looked at.
Anything from terrorism, hijack and suicide is being looked at.
Both Malaysia and China are looking into the terror angle with MAS CEO Ahmad Jauhari saying that the passenger manifest had been passed to the police to check the background of each passenger.
"We know the background of the crew and now the police are doing background checks on the passengers," he said.
Acting Transport Minister Datuk Seri Hishammuddin Hussein also said Beijing had been asked to look again at the passenger manifest although all of them had earlier been cleared by the Chinese.
The details of the probe into the stolen passports used by two Iranian passengers will be made public.
However, Home Minister Datuk Seri Dr Ahmad Zahid Hamidi said at the Dewan Rakyat that the details would be only made public "in due course".
Iranians Pouri Nour Mohammad Merhdad, 19, and Delavar Seyed Mohammad Erza, 29, raised a global stir when they reportedly flew here from Doha using Iranian passports and then switched to stolen Austrian and Italian passports to board the Malaysia Airlines flight to Beijing on March 8.
Initial investigations showed that Pouri Nour had planned to go to Germany to seek asylum and reunite with his mother in Frankfurt.
The passports held by Pouri Nour and Delavar were reported stolen in Thailand in the past two years.
More chilling, though, is a claim by an American expert that the plane's disappearance could be part of a suicide plot by a crew member.
A top terrorism expert told the New York Post that there was a growing consensus that this was a suicide by the pilot or co-pilot.
"They wanted to get as far away and land in the farthest and deepest part of the ocean," said Rep Pete King (R-LI), chair of the House Homeland Security Subcommittee on Counterterrorism and Intelligence.
King said the scheme might have hinged on the hope that family members could still collect life insurance on the dead pilot or co-pilot.
"If they never find the plane, they can't call it suicide," he claimed.
Hishammuddin did not discount the possibility when he was asked about it yesterday. It is also learnt that police are delving into the behaviour patterns of the crew members in the days prior to the flight.
King said the Americans believe the Beijing-bound airliner headed south towards the Indian Ocean after its "turnback" as some of the deepest spots of any ocean were to be found there.
King expressed doubt that the pilot and co-pilot were both in on the plan, adding: "One or the other would have to somehow silence the other."
The plane's sharp climb to 45,000 feet, as recorded by Malaysian military radar, would probably have "incapacitated" everyone outside the cockpit by rapidly reducing oxygen levels in the cabin, King told the Post.