Two men and a woman have been arrested in Essex on suspicion of assisting Russian intelligence.
Counter-terrorism officers detained the suspects, aged 41, 46 and 35, at two separate addresses in the town of Grays.
All three were taken to a London police station for questioning under the National Security Act.
Authorities believe the arrests are connected to efforts by Russian spy services to operate within the UK.
Police said searches are ongoing and stressed that the investigation remains active.
The arrests mark a significant escalation in Britain’s crackdown on foreign interference and covert activities.
