Chung Biu “Bill” Yuen, 66, and Chi Leung “Peter” Wai, 41, were found guilty last month of assisting a foreign intelligence service by conducting surveillance on prominent dissidents between December 2023 and May 2024.

Wai, who worked for the UK Border Force, was additionally convicted of abusing his position to access confidential government databases in search of information relating to surveillance targets.

The pair, both dual British and Chinese citizens, denied the allegations throughout the proceedings. Chinese authorities rejected the case, with the Chinese Embassy in London describing it as a politically motivated misuse of legal processes.

At London’s Old Bailey court, Judge Bobbie Cheema-Grubb sentenced Yuen to eight years in prison and Wai to 10 years, emphasizing the broader threat posed by modern foreign intelligence operations.

“The United Kingdom now faces persistent, adaptive, and often clandestine interference by foreign state actors and those acting on their behalf,” the judge said during sentencing.

She noted that contemporary espionage activities increasingly extend beyond the theft of military or state secrets and can include surveillance, intimidation and information gathering directed at political dissidents and individuals who have sought refuge under British law.

According to prosecutors, the defendants monitored prominent pro-democracy campaigners from Hong Kong who had relocated to Britain following political crackdowns in the Chinese territory.

The case forms part of growing concerns among British security agencies about foreign interference activities targeting diaspora communities, political activists and critics of overseas governments living in the United Kingdom.

Commander Helen Flanagan, head of counterterrorism policing in London, described the conduct of the two men as deeply troubling and said their activities were directed against individuals exercising democratic freedoms.

“The activity of Wai and Yuen was truly chilling,” Flanagan said.

“They were spying and targeting individuals in the UK who were pro-democracy campaigners and were simply protesting against the Hong Kong and Chinese government and authorities.”

Relations between London and Beijing have become increasingly strained in recent years over issues including Hong Kong, national security concerns, allegations of foreign interference and espionage-related investigations.

British authorities have repeatedly warned that foreign intelligence operations are becoming more sophisticated, often focusing on surveillance, influence campaigns and efforts to monitor critics living abroad.

The convictions mark a significant milestone in the United Kingdom’s efforts to counter foreign-state interference and reinforce legal protections for political dissidents residing in the country.