A UK Border Force officer and Hong Kong trade official based in London have been found guilty of spying for China and surveilling dissidents through a “shadow policing” operation.

Chi Leung “Peter” Wai, 38, and Chung Biu Yuen, 65, also known as Bill, were found guilty at the Old Bailey of assisting a foreign intelligence service, making them the first people in British history to be convicted of spying for China.

Wai, who worked for Border Force at Heathrow airport and volunteered as a City of London special constable, was also found guilty of misconduct in public office in relation to unauthorised searches of Home Office databases.

The two men, who had denied the charges, were found guilty by majority verdicts. Mrs Justice Cheema-Grubb will sentence the men, who are both dual Chinese and British nationals, at a later date.

Yuen, who was accused of giving Wai the targets to surveil, looked down as the verdict was heard. Wai stared ahead.

After 23 hours and 38 minutes of deliberation, jurors could not reach a verdict on charges against the men of foreign interference, a separate offence under the National Security Act. The prosecution said it would not seek a retrial.

A third accused man, 37-year-old former Royal Marine Matthew Trickett, who was charged under the National Security Act alongside Yuen and Wai in May 2024, was found dead in a park near his home in Maidenhead, Berkshire, a week after being bailed.

Prosecutors had asked the court to remand Trickett in custody for his own protection after he tried to take his own life in a police cell following his arrest. He told custody sergeants he would kill himself when he was released.

A nine-week trial heard that Wai gathered intelligence on the orders of Yuen, who was a senior manager at the Hong Kong Economic Trade Office (HKETO) in London, which was said to be an extension in the UK of the Hong Kong government.

The court heard that the targets included Nathan Law, an exiled politician who led the student protest movement in Hong Kong, who was the subject of multiple spying operations and has had a £100,000 bounty put on his head by the Chinese authorities.

The jury was told that Wai infiltrated Hong Kong pro-democracy groups and sought to gather information on British politicians including the former Conservative cabinet minister Iain Duncan Smith and the Labour peer Helena Kennedy.

The spying ring was uncovered when police thwarted an apparent attempt to kidnap Monica Kwong, a personal assistant who had fled Hong Kong in 2023 after being accused of defrauding her employer, Tina Zhou, out of £16m.

Wai was arrested on 1 May 2024 in Kwong’s flat in Pontefract, West Yorkshire, along with Trickett, then a serving Home Office immigration office, as well as Zhou and two former Hong Kong police officers who had flown to London to confront the personal assistant over the alleged fraud.

The group had sought to trick their way into Kwong’s home by posing as electricians who had come to repair a fuse, the court heard. Trickett poured bottled water on the floor to simulate a fake flood as part of one failed ruse to get Kwong out of the flat.

When the group subsequently broke in to Kwong’s home, police who had been bugging them were waiting to take the suspects into custody.

Wai, who was known to associates as Fatboy, denied he had been providing intelligence to Chinese authorities for years.

As a teenager he joined the Royal Navy in an engineering role, and he was placed on attachment with the Royal Marines before joining the Royal Navy police. He was also an instructor in the traditional Chinese martial art of lion dancing and his troupe had performed at 10 Downing Street.

He claimed that a chat group on which he was accused of sharing intelligence was to do with a company run by his lion dancing master and that he was simply passing on information about UK life. But jurors were shown messages between Yuen and Wai that the prosecution said showed them discussing plans to target activists, who were referred to as “cockroaches”.

The Chinese embassy in London has previously accused Britain of fabricating the allegations.