A senior source with ties to the Communist Party leadership said Beijing was reluctant to jeopardize recently improved ties with Washington.
The explosive revelations of the U.S. National Security Agency's (NSA) spying programs were provided by Edward Snowden, a former CIA employee and NSA contractor currently holed up in Hong Kong, a China-controlled city.
Snowden told the South China Morning Post, Hong Kong's main English language newspaper, last week that Americans had spied extensively on targets in China and Hong Kong.
He said these included the Chinese University of Hong Kong, the site of an exchange which handles nearly all the city's domestic web traffic. Other alleged targets included government officials, businesses and students.
At the briefing, Hua rejected a suggestion that Snowden was a spy for China.
"This is sheer nonsense," she said, without elaborating.
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It will likely be up to the central government to decide what happens if Washington requests Snowden's extradition, as Beijing controls Hong Kong's diplomatic affairs. The U.S. Justice Department is investigating the case but Snowden has not been charged with any crime.
In a poll on the website of the Global Times, a popular tabloid published by the Communist Party's official People's Daily, 98 percent of respondents said China should refuse to send him back to the United States.
"Unlike a common criminal, Snowden did not hurt anybody. His 'crime' is that he blew the whistle on the U.S. government's violation of civil rights," the newspaper said in an editorial.
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"His whistle-blowing is in the global public interest. Therefore, extraditing Snowden back to the U.S. would not only be a betrayal of Snowden's trust, but a disappointment for expectations around the world. The image of Hong Kong would be forever tarnished."
The former British colony of Hong Kong is supposed to enjoy wide-ranging autonomy and broad freedoms denied to people in mainland China, including an independent judiciary and free press.
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Since its return to Chinese rule in 1997, however, the city's pro-democracy politicians and activists have complained that Beijing has been steadily eroding Hong Kong's freedoms despite constitutional safeguards granting a high degree of autonomy.