Alleged spy's self-harm threat not passed on - inquest

Warning: This story contains details that some may find disturbing.

The Metropolitan Police did not tell another force a former Royal Marine later found dead had said he would harm himself after leaving custody, an inquest heard.

Matthew Trickett, 37, had appeared in court charged under the National Security Act and was found in a park in Maidenhead on 19 May 2024.

After being arrested on suspicion of assisting the Hong Kong intelligence service he was seen to attempt self-harm in his cell on 11 May. He was released on bail on 13 May.

A senior investigating Met Police officer said he and his team did not believe Trickett, who lived in Maidenhead, would be granted bail.

The officer, who has been given anonymity for the hearing and spoke behind a screen, said details of Trickett's case should have been passed onto Thames Valley Police.

"We thought Matt was going to be remanded in custody for the offences he was charged with," he said.

"Because of that I think there was less attention in terms of the investigation team, in terms of making sure those records were updated."

He said staff are meant to log any encounter with "an individual who is displaying vulnerabilities or risk".

The inquest being held at Reading Coroner's Court heard on Tuesday that Trickett had told officers he would not harm himself in custody, but would do so after he was released.

The senior officer said while people arrested in national security cases are in custody, paper records and not digital ones were used.

"Those specifics around what happened in custody weren't uploaded automatically as they would with a digital record and because of that there was failure for that information to be passed on to Thames Valley Police," he said.

He said there is now more oversight of people leaving the type of custody Trickett was in.

National Security Act teams have introduced a checklist "for every person leaving custody" which "tries to prevent the issues that have occurred here", the officer added.

Two co-defendants charged as part of the same investigation were jailed in June.