The 19-year-old asylum seeker checked onto the plane using a stolen Austrian passport, Malaysian police chief Khalid Abu Bakar said in Kuala Lumpur.
“We do not believe that he was part of a terrorist group,” said Abu Bakar. “Rather we believe that he was emigrating to Germany,” where his mother “was waiting for him”.
Malaysian police are in contact with the man's mother. The second Iranian passenger, also travelling on a stolen passport, was heading for Sweden, police said.
The two stolen passports were Austrian and Italian and were taken in Asia several years ago.
The Boeing 777 went missing on Saturday en route from Kuala Lumpur with 239 people on board, but no traces of the plane have been found yet.
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On Tuesday, rescue officials widened the search area, ordering dozens of ships and aircraft from nine countries to scour northern Malaysia, south Vietnam and the seas west of Malaysia.
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