A former university professor in China went on trial on Monday in Brooklyn on charges he acted as a Chinese agent by monitoring U.S.-based activists opposed to Beijing's Communist government at the direction of intelligence officials in China.

Federal prosecutors said Shujun Wang, a naturalized U.S. citizen, exploited his leadership role in New York communities supporting democracy in China to collect information on dissidents, and shared it with four officials in China's Ministry of State Security (MSS), an intelligence service.

Wang, who emigrated to the United States in 1994, was arrested in March 2022. He pleaded not guilty to four counts including acting as a foreign agent without notifying the U.S. attorney general and lying to U.S. authorities. Prosecutors said Wang's scheme ran from 2005 to 2022.

The U.S. Department of Justice has in recent years cracked down on what it calls "transnational repression" by U.S. adversaries such as China and Iran.

The term refers to the surveillance, intimidation and, in some cases, attempted repatriation or murder of activists against those governments.

Last year, a former New York City police sergeant was convicted of acting as an illegal Chinese agent by intimidating a U.S.-based fugitive to return to his homeland to face charges.

Wang, in his mid-70s, faces up to 25 years in prison if convicted. Jury selection began on Monday before U.S. Circuit Judge Denny Chin, who normally hears appeals, in Brooklyn federal court.

Prosecutors say MSS officials directed Wang to target Hong Kong pro-democracy activists, advocates for Taiwanese independence campaigners and Uyghur and Tibetan activists.

Defense lawyers said in a June 16 court filing that Wang communicated with Chinese officials to try to "infiltrate and subvert" China's government by spreading Western political ideas.

"Unfortunately, FBI Agents misunderstood him and his role," defense lawyer Kevin Tung wrote.

U.S. prosecutors also charged four Chinese intelligence officers who they say acted as Wang's handlers. Those officers are at large and believed to be in China.