Two men, including one who was reported to be a parliamentary researcher, were charged with spying for China, British prosecutors said on Monday.

The police said Christopher Berry, 32, and Christopher Cash, 29, were charged with “providing prejudicial information to a foreign state, China". They will appear at Westminster Magistrates' Court on Friday.

The police allege that the two men collected, recorded or communicated information “prejudicial to the safety or interests of the state” and violated the Official Secrets Act between late 2021 and February 2023.

“This has been an extremely complex investigation into what are very serious allegations,” said Dominic Murphy, head of the Metropolitan Police counterterrorism command.

Authorities did not release details about the two men. But Berry is reportedly an academic based in Oxfordshire, and The Sunday Times reported last year that Cash was a parliamentary researcher who held a pass that allows full access to the Parliament buildings, issued to lawmakers, staff and journalists after security vetting.

The report said Cash worked with senior lawmakers from the governing Conservatives, including Alicia Kearns, who now heads the powerful Foreign Affairs Committee, and her predecessor in that role, Tom Tugendhat, who is now security minister.

British Prime Minister Rishi Sunak said last year that he raised the issue with Chinese Premier Li Qiang, saying he raised “very strong concerns” about interference in British democracy.

At the time, Cash issued a statement through his lawyers maintaining his innocence. The Chinese embassy issued a statement calling the allegations fabricated.

Also on Monday, three people were arrested in Germany on suspicion of spying for China and arranging to transfer information on technology with potential military uses.

British intelligence authorities have ratcheted up their warnings about Beijing's covert activities in recent years.