A former Royal Marine charged with spying for the Hong Kong intelligence service has died in “unexplained circumstances”, according to police.

Officers from Thames Valley Police were called to Grenfell Park in Maidenhead by a member of the public, The Times reports. Despite attempts from medics, Matthew Trickett, 37, was pronounced dead at the scene. 

Trickett has been alleged to have agreed to undertake information gathering, surveillance and acts of deception that were likely to assist a foreign intelligence service.

Police arrived at the scene at 5.15pm and have now launched an investigation into the incident.

A spokesman for Thames Valley Police said: “An investigation is ongoing into the death, which is currently being treated as unexplained.

“Formal identification has taken place and we can confirm the man is Matthew Trickett, aged 37, from Maidenhead.

“His family have been informed and they are being supported by officers. We would kindly ask that their privacy is respected at this difficult time.  

“A post-mortem will be conducted in due course.”

Trickett was on bail, awaiting court proceedings, which required him to register at a police station regularly. Meaning that because police had prior contact with Trickett, a mandatory referral was made to the Independent Office for Police Conduct (IOPC), which is the normal process where there has been a death following police contact.

The IOPC has assessed the referral and decided the matter should be investigated by Thames Valley Police’s professional standards department.

Anyone with information is being asked to come forward, particularly anyone who was in Grenfell Park on Sunday afternoon prior to 5.15pm. 

Those who have information should call 101 quoting reference 43240233265.