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.
HONG KONG — The request from the United States that Hong Kong detain Edward J. Snowden, who has been accused of stealing government secrets, before it seeks his return to America is likely to set off a tangled and protracted fight, with Mr. Snowden and his legal advisers having multiple tools to delay or thwart his being surrendered to American officials.
Mr. Snowden’s exact location was unclear Saturday, though he was believed to be hiding in a safe house in Hong Kong after leaving a hotel room two weeks ago upon revealing that he was the one who had leaked details of American surveillance efforts to the media. Hong Kong police officials would not comment Saturday about Mr. Snowden’s whereabouts.
Stephen Vickers, who oversaw police criminal intelligence in Hong Kong before Britain returned the territory to China in 1997, said Saturday that the Hong Kong police had certainly figured out where Mr. Snowden was hiding and should be able to detain him once Hong Kong government lawyers determined that the charges Mr. Snowden faced in the United States were also legal offenses in Hong Kong.
“I have no doubt whenever the government decides to take action, they will pick him up fast,” said Mr. Vickers, who now runs a risk consulting firm.