CNN said it obtained a confidential alert from the Canadian Border Services Agency, issued after the Oct. 29 incident on Air Canada Flight AC018. The alert called the man's feat "an unbelievable case of concealment."
The man sought refugee status after he was escorted from the plane in Vancouver, CNN reported. Canadian officials have released few details about the case because of privacy laws.
Border agents found a head and neck mask, a cap and a brown cardigan in the man's luggage. The alert said he demonstrated his disguise for them.
The alert suggested the man switched boarding passes with a U.S. citizen before getting on the plane. During the flight, he reverted to his normal appearance, removing his disguise in a bathroom and coming out as a man who appeared to be in his early 20s.
An Air Canada spokesman said security is very tight in Hong Kong, with all passengers who begin their travel there required to go through passport control run by the Chinese government.