LONDON (Reuters) - British police are investigating the unexplained death of a man charged earlier this month with assisting Hong Kong's foreign intelligence service.

Police said in a statement they were investigating an unexplained death having received a call from a member of the public on Sunday. The man pronounced dead at the scene in Maidenhead, southern England, was named in the statement as 37-year-old Matthew Trickett.

A statement from Trickett's solicitor said he was shocked at his client's death and would be unable to comment further while the investigation was ongoing. In the same statement, the family said they were "mourning the loss of a much-loved son, brother, and family member".

Trickett, a former Royal Marine with a private security firm, was one of three men granted bail at a May 13 court hearing after being charged with two offences under Britain's National Security Act.

The National Security Act was passed last year and introduced new measures to target threats from foreign states.

The case has fuelled a diplomatic row between Britain and China. Britain's foreign ministry summoned the Chinese ambassador on May 14 to state that espionage and cyber attacks were not acceptable on British soil.

The Chinese Embassy in London accused Britain of fabricating the charges against the men and said it had no right to interfere in Hong Kong's affairs

(Reporting by William James; Editing by Sandra Maler)