A UK immigration officer who secretly used confidential government databases to monitor Hong Kong dissidents living in Britain has been convicted of spying for Chinese intelligence in a case that has raised alarm over foreign surveillance activities operating inside the UK.

Chi Leung “Peter” Wai, 38, was found guilty under the National Security Act after prosecutors accused him of assisting Chinese intelligence-linked operations targeting pro-democracy activists who fled Hong Kong following Beijing’s crackdown on dissent.

The court heard that Wai abused his role as a Border Force officer at Heathrow Airport to access sensitive immigration records and track the movements of Hong Kong dissidents in Britain.

Wai was convicted alongside Chung Biu “Bill” Yuen, 65, a former Hong Kong police officer who later became office manager at the Hong Kong Economic and Trade Office (HKETO) in London.

According to reports, Yuen had relocated to Britain shortly after retiring from the Hong Kong Police Force in 2015, joining his wife and children in London through his dual British-Hong Kong citizenship. He later took up a role at HKETO, an office established to promote trade relations between Hong Kong and the UK, but which prosecutors said became increasingly politicised after the 2019 pro-democracy protests.

The court heard that Wai and Yuen were introduced in 2017 through Chu Ting Tang, a prominent figure in London’s Chinatown community known for his support of Beijing’s policies in Hong Kong.

After Wai joined Border Force in 2020, prosecutors said he began using his official access to Britain’s immigration database to gather intelligence on recently arrived Hong Kong activists.

In one message shown during the trial, Wai reportedly wrote to former Hong Kong Police Intelligence Chief Eddie Ma: “Will not let any cockroaches in,” referring to dissidents.

When Wai later sent information about Hong Kong activists entering Britain, Ma allegedly replied, “The head office seems to be interested at these informations.”

The court heard that Wai eventually began reporting directly on the activities of protesters and dissidents living in the UK while also drawing another Border Force officer, former Royal Marine Matthew Trickett, into the operation.

Trickett, who reportedly undertook private security work alongside his Home Office role, later assisted Wai in gathering information on pro-democracy campaigners.

The surveillance activities intensified after Hong Kong authorities in 2023 announced HK$1 million bounties on several overseas democracy activists, including campaigners Nathan Law and Finn Lau.

Prosecutors said Wai tasked Trickett with arranging surveillance on Nathan Law during a visit to the Oxford Union in November 2023.

Wai was also convicted of misconduct in public office for misusing official government systems to support the operation.

MI5 Investigation Uncovered Covert Surveillance Network

Chung Biu Bill Yuen — Chung Biu “Bill” Yuen

Meanwhile, Britain’s domestic intelligence agency MI5 uncovered the alleged surveillance network in 2024 after investigators began tracking efforts by the group to locate a Hong Kong woman living in northern England.

Court proceedings revealed that Wai allegedly used his access to the UK’s Atlas immigration database to trace Monica Kwong, a Hong Kong woman accused of stealing money from her former employer, a claim she strongly denied.

Kwong had been living in Pontefract with her young son when Wai reportedly confirmed her address through the staged delivery of a parcel before surveillance activities around her apartment intensified.

According to prosecutors, the operation escalated on 30 April 2024 when Tina Zou, who claimed Kwong owed her money, arrived at Heathrow Airport accompanied by colleagues and several former Hong Kong police officers.

The court heard that Wai and fellow Border Force officer Matthew Trickett then coordinated plans for the group to travel to Pontefract, allegedly with the knowledge of Chung Biu “Bill” Yuen, in what prosecutors described as an attempt to confront Kwong directly.

During the trial, evidence showed that members of the group used a “snake camera” to film underneath the apartment door, while Trickett left behind a note identifying himself as “Dave from maintenance.”

Prosecutors further told the court that water was later poured beneath the door under the pretence of investigating a leak in an effort to force contact with the occupant.

On 1 May 2024, the group eventually forced entry into the apartment, only to discover that it was empty. Unbeknown to those involved, MI5 had already installed an audio surveillance device inside the property, which recorded the incident.

Shortly after police intervened, prosecutors said Wai attempted to dispose of a fake warrant card identifying him as a superintendent with the City of London Police by throwing it out of a window.

Jurors later failed to reach a verdict on whether the Pontefract incident constituted foreign interference under national security laws, prompting prosecutors to confirm that no retrial would be sought on that charge.

Following the arrests and initial court appearances of Wai, Yuen and Trickett, Trickett was later found dead in Grenfell Park in Maidenhead in what authorities described as a suspected suicide.