"We have looked and re-looked at all the footage. They are not Asian-looking men," Datuk Azharuddin Abdul Rahman, director-general of the Civil Aviation Department said during the most recent press briefing by Malaysian authorities for Monday.
Azharrudin declined to answer about the men's possible ethnicity, saying security experts were investigating, Bernama reported.
The passports used by the two passengers reportedly were stolen in Phuket, Thailand, during the summer, Asian News International reported. Investigators were trying to determine if any other passengers were traveling on false documents.
The Beijing-bound MAS Flight MH370, carrying 227 passengers and 12 crew members, went missing about an hour after departing from Kuala Lumpur, Malaysia, for Beijing.
He also said an examination of video security footage from the departure area at the Kuala Lumpur airport indicted security protocol was followed.
"The team of investigators is looking into the matter. All security protocol has been complied. There is a possibility of a stolen passport syndicate," Azharrudin said.
Azharuddin said the search-and-rescue operation for the missing Boeing 777-200 was expanded from 50 nautical miles to a 100-nautical radius within the Igari sea area and up to North Sumatra by land. He said the search was being conducted "block by block."
Officials searching for the missing Malaysia Airlines jet said they were considering all possible scenarios, including a disintegration or explosion, the (Malaysia) Star reported.
"We are not ruling out the possibility [of an explosion or disintegration] but the main focus is to find the plane," Azharuddin said. "Such theories are being explored but we have to avoid from speculating on the matter."
Azharuddin said different countries had contributed 34 aircraft and 40 vessels to help in the search.
On Sunday, officials said debris found near Vietnam waters was not from the missing plane.