In return for safe passage home in 2018, Tang, now 67, allegedly agreed to work for China’s state security ministry, providing information on other dissidents. According to an FBI witness statement now disclosed at a US federal court in New York, he took videos of dissident events and campaigns, and allowed his phone to be bugged by state security agents. He also recorded an online memorial meeting to honour victims of the Tiananmen Square massacre, and helped an agent or agents join a social media chat group for dissidents.

“The defendant, and others known and unknown, knowingly acted in the United States as an agent of a foreign government — to wit, the People’s Republic of China,” the indictment reads.

He is just one of a number of Chinese to have been accused of spying after the US justice department launched a broad investigation into attempts to monitor dissidents overseas by the Beijing authorities.

Wang Shujun, 75, denied but was found guilty last month of acting as a foreign government agent, also in New York. An academic, he established a dissident group on which he reported for the Chinese authorities.

This month, Linda Sun, deputy chief of staff to the governor of New York state, was also arrested and accused of being a Chinese agent.

And in a separate case, on Wednesday Alexander Ma Yuk-ching, 71, a Hong Kong-born US citizen who once worked for the CIA, reached a plea deal and was sentenced to ten years in jail. He was accused with his brother, who also worked for the CIA but has since died, of providing information to Chinese agents in return for money and gifts including a set of golf clubs.

“I hope God and America will forgive me for what I have done,” Ma wrote to the judge as part of his plea deal.

Tang’s case has sent shockwaves through New York’s dissident movement, in part because of his ties to the China Democracy Party and Wang Juntao, one of the leaders of the Tiananmen Square democracy movement.

Mike Gao, a Chinese-American lawyer who knew Tang, told Radio Free Asia (RFA) that his friend had become disillusioned with the exile movement as he grew older, but that even so his arrest had made Chinese dissidents more cautious.

Tang was older than the main body of 1989 student protesters. He had been until then a factory worker in his home province of Jilin in northeast China.

Originally sentenced after the protests to 20 years, he was released early, but maintained his links with other activists. In particular, he campaigned for the China Democracy Party, founded by Wang Juntao and other “black hands”, as China called the main organisers of the 1989 protest movement.

Wang served 13 years after 1989 after being captured while trying to escape to Hong Kong, and was sent into exile in the US in 1994. He then became the centre of a group of dissidents in Flushing, a district of Queen’s in New York.

That was where Tang moved too, after his own 2002 escape from China. He settled down and married an American woman, Jen Salen, not of Chinese descent but with a background in China studies, although they divorced this year.

Salen, who worked for a congressional committee as a China researcher, might have been a target for the Chinese agents. Tang told RFA through an intermediary that he never informed his wife of his contacts with the agents.

Among those people Tang did target was another Tiananmen Square protester, Xiong Yan, who stood for Congress in 2022 but lost a Democratic Party primary. Tang took videos of campaign events, the FBI said without naming Xiong, and provided other information.

Xiong Yan is a China-born naturalised American and was a dissident involved in the Tiananmen Square protests

WIKIPEDIA

All this occurred after Tang’s mother and brother fell sick. In 2018 he was allowed to return home after he agreed to meet state security agents. The ministry of state security also paid his family money, according to reports, though both his mother and brother have since died.

China regularly denies interfering in the internal affairs of other countries, and insists that Chinese abroad must “obey the laws of host countries”. Tang has yet to enter a plea.