Three people have been arrested on suspicion of spying for China. The arrests were made in Wales and London as part of a Counter Terrorism Policing investigation into suspected National Security Act offences, the Metropolitan Police said on Wednesday.

The force said the suspects, aged 39, 43 and 68, were arrested on March 4 by counter-terrorism officers on suspicion of assisting a foreign intelligence service – contrary to section 3 of the National Security Act, 2023. The country to which the investigation relates is China, the Met Police added.

All three men remain in custody and searches have been carried out at the addresses where they were arrested – London, Powys and Pontyclun, the force also said.

As part of the investigation being led by the Counter Terrorism Policing London, searches were also carried out at three other addresses in London, East Kilbride and Cardiff respectively.

The arrests and search activity was supported by colleagues from CTP Wales and CTP Scotland.

After the arrests, Commander Helen Flanagan, head of Counter Terrorism Policing London, said: “We have seen a significant increase in our casework relating to national security in recent years, and we continue to work extremely closely with our partners to help keep the country safe and take action to disrupt malign activity where we suspect it.

“Today’s arrests are part of a proactive investigation and while these are serious matters, we do not believe there to be any imminent or direct threat to the public relating to this. Our investigation continues, and we thank the public for their ongoing support.”

Enquiries remain ongoing.