A former Royal Marine who died in “unexplained” circumstances after being accused of spying for <a href="https://www.thenationalnews.com/tags/hong-kong/" target="_blank">Hong Kong</a> has been described as a “much-loved son, brother and family member”. Matthew Trickett, 37, an immigration enforcement officer and private investigator from Maidenhead, Berkshire, was also accused of foreign interference and had appeared at Westminster Magistrates' Court with two other people last week. He was found by a member of the public in a park in Maidenhead, outside <a href="https://www.thenationalnews.com/tags/london/" target="_blank">London</a>, on Sunday afternoon. Mr Trickett received emergency treatment but was pronounced dead at the scene. Police said his death is being treated as unexplained. A family statement said: “We are mourning the loss of a much-loved son, brother and family member.” Mr Trickett's solicitor Julian Hayes, senior partner at Berris Law, said: “It has sadly been confirmed by Thames Valley Police that the body found in Grenfell Park, Maidenhead, on Sunday was that of our client Matthew Trickett. “We are naturally shocked at this news and supporting his family as best we can. “The death is currently being treated as unexplained by the police and further investigations are still ongoing.” Mr Trickett, alongside Chi (Peter) Leung Wai, 38, from Staines, Surrey, and Chung Biu Yuen, 63, from Hackney, east London, were charged under the National Security Act after an investigation by the Metropolitan Police Counter Terrorism Command. The charges allege that between December 20 last year and May 2, the three men agreed to undertake information gathering, surveillance and acts of deception that were likely to materially assist a foreign intelligence service. It is also alleged that on May 1 they forced entry into a UK residential address, being reckless as to whether the prohibited conduct, or course of conduct of which it forms part, would have an interference effect. They had all been bailed and were due to appear at the Old Bailey on Friday. Hong Kong authorities have confirmed that Mr Yuen was the office manager of the Hong Kong Economic and Trade Office in London. Mr Trickett was formerly employed by the UK Border Force at Heathrow Airport, before joining Home Office Immigration Enforcement on February 21 this year. He was also the director of MTR Consultancy, a security firm formed in April 2021. Prosecutor Kashif Malik said during last week's hearing that Mr Trickett had attempted suicide after being charged, and asked for the defendant to be remanded in custody for his own welfare. Thames Valley Police referred itself to the Independent Office for Police Conduct (IOPC) because Mr Trickett's bail condition required him to regularly register at a police station. The IOPC assessed that referral and decided the matter should be investigated by the police force's professional standards department. A police cordon was in place in Grenfell Park on Tuesday evening with several officers stationed next to a black forensics tent close to a children's playground. More officers were positioned at vantage points and paths around the park. A local resident said “there were children everywhere” in the park on Sunday when Mr Trickett was found dead by police. Tatiana Dioniseva, 30, said: “On Sunday there were so many people here – there were children everywhere. “It was a bit bizarre because it was sunny – there were children about and then a crime scene over there.” She said Grenfell Park, close to Maidenhead station, was popular, adding: “Usually on Sundays, every bench will literally be taken. “There are people everywhere – it's a popular place.” <a href="https://www.thenationalnews.com/tags/china/" target="_blank">Chinese authorities</a> in the UK and Hong Kong have decried the charges, saying they were the latest in a series of “groundless and slanderous” accusations that the UK government has levelled against China. Hong Kong's government demanded that the UK provide full details of the allegations and protect the rights of the office manager of the trade office. The former British colony, returned to Chinese control as a semiautonomous territory in 1997. More than 100,000 Hong Kongers have moved to the UK since Beijing imposed a sweeping national security law triggered by the huge anti-government protests in the city in 2019. Britain’s government has established a <a href="https://www.thenationalnews.com/world/asia/china-no-longer-recognises-uk-issued-hong-kong-passports-1.1156028" target="_blank">fast-track immigration route for the migrants</a>, many of whom want to settle in the UK because of dwindling civil liberties in their home city. Rights groups have warned that Hong Kongers who have moved to Britain continue to face “transnational repression” by supporters of the Chinese government. UK officials have been increasingly vocal in warning about security threats from Beijing, and recently accused China of being behind a string of cyberespionage operations targeting politicians and Britain's election watchdog. In a separate and ongoing court case, two men, <a href="https://www.thenationalnews.com/world/uk-news/2023/09/17/uk-foreign-secretary-cleverly-has-no-regrets-over-china-trip-despite-alleged-spy-arrest/" target="_blank">including a parliamentary researcher</a>, were recently charged with spying for China. Christopher Cash and Christopher Berry were charged with violating the <a href="https://www.thenationalnews.com/world/uk-news/2023/09/10/two-people-arrested-under-official-secrets-act/" target="_blank">Official Secrets Act</a> by providing information or documents that could be “useful to an enemy”.