Three men appear in UK court charged with helping Hong Kong's foreign intelligence service

Chung Biu Yuen, 63, Chi Leung Wai, also known as Peter Wai, 38, and Matthew Trickett, 37, were arrested earlier this month following an investigation by the Metropolitan Police's Counter Terrorism Command.

The trio were each charged with two offences under Britain's National Security Act, which was passed last year and introduced new measures to target threats from foreign states.

They are accused of assisting a foreign intelligence service between December and May by "agreeing to undertake information gathering, surveillance and acts of deception" in Britain, according to the charges.

Hong Kong was under British rule for 156 years before reverting to Chinese sovereignty in 1997.

Spying allegations against China and Russia have been piling up in Western nations in recent years, with Beijing and Moscow scoffing at them as part of a global smear campaign.

The second charge alleges the three men conducted "foreign interference" by forcing entry into a residential address in Britain on May 1.

The three men appeared in the dock at Westminster Magistrates' Court, where they spoke only to confirm their names, dates of birth and address.

They were not asked to enter any pleas to the charges and they will next appear in court at the Old Bailey on May 24. All three men were granted bail.

The Metropolitan Police earlier said a total of 11 people were detained this month, nearly all in the Yorkshire area of northern England.

"While these offences are concerning, I want to reassure the public that we do not believe there to be any wider threat to them," Commander Dominic Murphy, Head of the Met's Counter Terrorism Command, said in a statement.

Seven men and one woman who were not charged were released from custody, police said, adding that the investigation is ongoing.

Police said the charges against the three men were not linked to a separate investigation involving Russia, which was also conducted under the same national security law.

There was no immediate response from Hong Kong's Economic and Trade Office in London, Hong Kong's Security Bureau, or the Hong Kong police.