Updated

China sentenced a 78-year-old U.S. citizen to life in prison on Monday on spying charges, a case that could further deteriorate already damaged ties between Beijing and Washington, D.C.

John Shing-Wan Leung, who also holds permanent residency in Hong Kong, was detained on April 15, 2021, by the local bureau of China's counterintelligence agency in the southeastern city of Suzhou, the city’s intermediate court said in a statement.

Details of the charges have not been publicly released.

His detention came right after the country closed its borders and imposed tight restrictions in response to the coronavirus pandemic.

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China sentenced a 78-year-old U.S. citizen to life in prison on Monday on spying charges. (Getty)

The Suzhou court offered no indication of a connection to China-U.S. relations, but spying charges are highly selective, and no evidence has been released – a standard practice among many countries aiming to secure their personal connections, networks and access to information, according to The Associated Press.

Investigations and trials in cases like this one are held behind closed doors and public information is generally limited outside vague allegations of infiltration, gathering secrets and threatening state security.

The U.S. Embassy in Beijing told The AP it was aware of the case, but could not comment further because of privacy concerns.

"The Department of State has no greater priority than the safety and security of U.S. citizens overseas," the embassy said in an email.

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The U.S. Embassy in Beijing said it was aware of the case, but could not comment further because of privacy concerns.  (Getty)

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Chinese prosecutors have a strengthened ability to hold people charged in national security cases, and long pretrial detentions are not uncommon. 

Requests for more information and court appeals are typically blocked by the country's authoritarian political system and the ruling Communist Party's complete control over legal matters, civil society and freedom of information.

The Associated Press contributed to this report.