Edward Snowden, the United States intelligence whistleblower, could remain stuck in limbo in a Moscow airport for weeks or months.
Russian media reported a source "close to Mr Snowden" saying that he could be forced to stay in Russia indefinitely because US authorities had annulled his passport.
President Vladimir Putin said on Wednesday that the former CIA and National Security Agency technician was staying legally in the transit area of Sheremetyevo Airport after flying in on Monday from Hong Kong, where he leaked details of widespread surveillance by US security services of American citizens' emails and telephone calls.
There appeared little urgency over his departure. The Daily Telegraph and other media scoured Sheremetyevo's three southern terminals yesterday but airport staff, receptionists at a capsule hotel, policemen, Russian consular officials and passengers all claimed they had not seen the American.