By Tabassum Zakaria and Mark Hosenball
WASHINGTON, June 21 (Reuters) - The United States has filed espionage charges against Edward Snowden, a former U.S. National Security Agency contractor who admitted revealing secret surveillance programs to media outlets, according to a court document made public on Friday.
Snowden, who is believed to be in hiding in Hong Kong, was charged with theft of government property, unauthorized communication of national defense information and willful communication of classified communications intelligence information to an unauthorized person, said the criminal complaint, which was dated June 14.
The latter two offenses fall under the U.S. Espionage Act and carry penalties of fines and up to 10 years in prison.
A single page of the complaint was unsealed on Friday. An accompanying affidavit remained under seal.
The charges are the government's first step in what could be a long legal battle to return Snowden from Hong Kong and try him in a U.S. court.
Two U.S. sources, speaking on condition of anonymity, said the United States was preparing to seek Snowden's extradition from Hong Kong, which is part of China but has wide-ranging autonomy, including an independent judiciary.
The Washington Post, which first reported the criminal complaint earlier on Friday, said the United States had asked Hong Kong to detain Snowden on a provisional arrest warrant.
There was no immediate response to requests for comment from Hong Kong's security bureau.
Snowden earlier this month admitted leaking secrets about classified U.S. surveillance programs, creating a public uproar. Supporters say he is a whistleblower, while critics call him a criminal and perhaps even a traitor.
He disclosed documents detailing U.S. telephone and Internet surveillance efforts to the Washington Post and Britain's Guardian newspaper.
The criminal complaint was filed in the Eastern District of Virginia, where Snowden's former employer, Booz Allen Hamilton, is located.
That judicial district has seen a number of high-profile prosecutions, including the spy case against former FBI agent Robert Hanssen and the case of al Qaeda operative Zacarias Moussaoui. Both were convicted.
'ACTIVE EXTRADITION RELATIONSHIP'
Documents leaked by Snowden revealed that the NSA has access to vast amounts of Internet data such as emails, chat rooms and video from large companies such as Facebook and Google, under a government program known as Prism.
They also showed that the government had worked through the secret Foreign Intelligence Surveillance Court to gather so-called metadata - such as the time, duration and telephone numbers called - on all calls carried by service providers such as Verizon.
President Barack Obama and his intelligence chiefs have vigorously defended the programs, saying they are regulated by law and that Congress was notified. They say the programs have been used to thwart militant plots and do not target Americans' personal lives, they say.
U.S. federal prosecutors, by filing a criminal complaint, lay claim to a legal basis to make an extradition request of the authorities in Hong Kong, the Post reported. The prosecutors now have 60 days to file an indictment and can then take steps to secure Snowden's extradition from Hong Kong for a criminal trial in the United States, the newspaper reported.
The United States and Hong Kong have "excellent cooperation" and as a result of agreements, "there is an active extradition relationship between Hong Kong and the United States," a U.S. law enforcement official told Reuters.
An Icelandic businessman linked to the anti-secrecy group WikiLeaks said on Thursday he had readied a private plane in China to fly Snowden to Iceland if Iceland's government would grant asylum.
Iceland refused on Friday to say whether it would grant asylum to Snowden. (Editing by Warren Strobel and Peter Cooney)