A former Royal Navy serviceman accused of spying for Hong Kong has been found dead, authorities cited by the BBC said. Matthew Trickett, 37, was found in a park in Maidenhead, west of London, UK, by a member of the public on Sunday. Emergency services were called at 5:15pm and attempted CPR, but he was pronounced dead at the scene. Trickett had appeared in court last week charged under the National Security Law. "An investigation is underway into the death, which is being treated as unexplained," Thames Valley Police said, adding that a post-mortem examination will be carried out. "We are devastated by the loss of a much-loved son, brother and family member," his family said in a statement cited by Sky News. Trickett was one of three people charged with aiding Hong Kong's security services and foreign interference. Chi Leung (Peter) Wai, 38, Matthew Trickett, 37, and Chung Biu Yuen, 63, were arrested in early May. The charges against them under the UK's National Security Law are scant on detail and add to a series of cases that have raised concerns about Chinese espionage in European countries. The men are accused of gathering intelligence and carrying out surveillance "likely to assist a foreign intelligence service in carrying out activities prejudicial to the safety or interests of the United Kingdom" between 20 December 2023 and 2 May 2024. They have also been charged with trespassing on a residential property on 1 May. In a statement, the Chinese foreign ministry in Hong Kong "strongly condemned" the British government for "fabricating charges, arbitrarily detaining Chinese citizens and smearing" the Hong Kong government. Beijing accused the UK of "interfering in Hong Kong's affairs" and threatened "resolute and strong countermeasures" if it did not "correct its mistakes". [News updated at 8:09pm] Read Also: London summons Chinese ambassador over alleged interference in the UK (Portuguese version)