Russia has denounced as claims of its involvement in Edward Snowden's travel plans "groundless and unacceptable".
More than two days after Mr. Snowden reportedly flew to Moscow from Hong Kong, his whereabouts remain unknown.
Journalists continue their vigil at Moscow’s Sheremetyevo Airport where Mr. Snowden’s flight landed on Sunday afternoon and from where he was to continue his journey to Cuba on Monday.
However, the ex-CIA officer played cat-and-mouse with the world media, failing to show up for the Aeroflot flight to Havana for which he had been booked and two dozen reporters boarded the plane to take pictures of his empty seat during the 12 hour journey.
Another Havana-bound flight left the Sheremetyevo Airport Tuesday afternoon with no sight of Mr. Snowden on board.
Russian foreign Minister Sergei Lavrov denied any knowledge of Mr. Snowden's movements.
"Russia has nothing to do with Mr. Snowden's movements; he chose his route himself and did not cross the Russian border", Mr. Lavrov said.
A Sheremetyevo Airport source told the Voice of Russia radio station on Tuesday that Mr. Snowden had left Moscow on Monday, but would not provide any further details.
Russian authorities have denied any involvement in Mr Snowden’s adventures, but experts doubt security services have missed a golden chance to interview the U.S. National Security Agency whistleblower.
"I’m sure officials interested in the Prism surveillance programme would want to speak with Mr. Snowden before he leaves Russia", said Alexander Konovalov, head of the Strategic Analysis.