Chi Leung Peter Wai, an immigration officer with the UK Border Force at Heathrow Airport, and Chung Biu Bill Yuen, a retired Hong Kong police superintendent, have been found guilty of espionage on behalf of Chinese intelligence. The operation involved the surveillance of Hong Kong dissidents in the UK, particularly after the 2019 protests in Hong Kong. Prosecutors revealed that Wai accessed classified immigration databases to gather information on pro-democracy activists, including Nathan Law, who is currently in exile in Britain. The espionage activities took place between 2023 and 2024 and were described as 'shadow policing' for Hong Kong and China. Evidence presented included encrypted messages discussing the surveillance of dissidents and British politicians. The case is significant as it represents the first successful prosecution for espionage under the modified National Security Act in the UK. China has dismissed the allegations as politically motivated. The trial also highlighted the mysterious death of Matthew Trickett, a former Royal Marine involved in the inquiry, raising further questions about the case's implications.