A Chinese court said it sentenced a 78-year-old American citizen to life in prison Monday on unspecified charges of spying, the latest in a wave of espionage cases that authorities have pursued amid growing wariness of foreign influence in the country.

The Intermediate People’s Court in the southeastern city of Suzhou said in a short statement that it had pronounced John Shing-Wan Leung guilty of espionage and sentenced him. It said that Leung was arrested in April 2021 by state security officials but provided no details about the charges or the circumstances of his detention or trial. The court also ordered the confiscation of about $70,000 worth of his personal property.

Leung holds a U.S. passport and is a permanent resident of Hong Kong, according to the statement posted on the court’s social media account.

The court in Suzhou did not respond to multiple requests for comment. A spokesperson for the U.S. Embassy in Beijing said the embassy was aware of the reports about the case but declined to comment because of privacy concerns. American citizens arrested in China must sign a privacy waiver to allow embassies and consulates to release information about their cases to the public.

Trials in China on charges of espionage or other sensitive political issues are often shrouded in secrecy, with proceedings closed to the public and the news media. Courts are controlled by the ruling Communist Party.

China has recently stepped up actions against what it sees as a growing threat of spies through a wave of raids, inspections and arrests targeting businesses with foreign ties as well as individuals.

In March, Beijing detained a Japanese business executive from a pharmaceutical company for espionage. Last year, authorities arrested a high-ranking editor of a Chinese Communist Party newspaper while he was having lunch with a Japanese diplomat, accusing the editor of acting as an agent for Japan or the United States, his family says.

Chinese officials have raided the offices or interrogated the staff of U.S. consulting firms such as the Mintz Group and Bain & Co. Most recently, state media announced a crackdown on the consulting industry in the name of national security, singling out Capvision Partners, a consulting firm with offices in New York and Shanghai. In describing the crackdown, China’s state broadcaster CCTV accused Western countries of stealing intelligence in key industries, including defense, finance, energy and health, as part of a “strategy of containment and suppression against China.”

Last month, China approved revisions to a counterespionage law that expanded the kinds of activities that could land foreigners behind bars. Experts say the amendments, which go into effect in July, could criminalize a range of mundane tasks related to information gathering such as the work of journalists and due diligence research on companies. Foreign businesses have already begun to reassess their operations in China and increase protections for employees.

The case of Leung was unusually severe given his age, a factor that Chinese courts tend to consider when handing down punishments, said Alfred Wu, an associate professor at the Lee Kuan Yew School of Public Policy at the National University of Singapore.

“Very few people get life sentences in my memory, so there must be something quite severe about his case,” he said, noting that 10 years was a more typical term for espionage.

Wu also said that the lack of information in the court’s statement suggested a high level of sensitivity around the case. Authorities generally tend to provide more details about criminal cases to deter would-be offenders, he said.

Little public information was available about Leung that could immediately be verified. Some news reports in Hong Kong speculated that he held positions in associations that promoted ties between China and the United States.

In 2004, People’s Daily, a Communist Party newspaper, featured someone with the same date of birth as Leung and the same Chinese name — Liang Chengyun — in an article about the pride of the Chinese diaspora around the world in seeing China’s growing strength.

In the article, People’s Daily said that man had been born in Hong Kong and moved to Britain for school when he was 16. It said he had worked at the United Nations headquarters in New York, and did business in the United States. He later held positions at a number of organizations that helped to foster trade and cultural exchanges between the United States and China. The paper said the man loved China and wanted the country to be unified with Taiwan.

Several China-related associations based in the United States that promote cultural exchanges did not immediately respond to requests for comment.

This article originally appeared in The New York Times.