MOSCOW — Intrigue deepened on Monday over the whereabouts of Edward J. Snowden, the fugitive former National Security Agency contractor accused of espionage, when he did not leave Moscow on a planned flight to Havana, one day after Hong Kong frustrated his American pursuers by allowing him to fly out of the territory.
Mr. Snowden’s vacant seat on the Havana flight raised the possibility that the Russian government had detained him, either to consider the demands by the Obama administration to intercept him and return him to the United States or perhaps to question him for Russia’s own purposes.
The authorities in Hong Kong said Mr. Snowden boarded an Aeroflot flight to Moscow’s Sheremetyevo airport that arrived on Sunday afternoon. But he was never photographed in Hong Kong and has not been seen publicly or photographed since his reported arrival in Moscow. Arriving passengers on that flight, interviewed at the airport, said they could not confirm that he had been aboard.
The situation remained infuriating for American officials, who have charged Mr. Snowden with illegally disclosing classified documents about American surveillance programs.