Three individuals were taken into custody on suspicion of gathering intelligence for the benefit of Moscow, according to investigative bodies.
An individual aged 41 and a 35-year-old woman were detained at a property located in Essex. A 46-year-old man was also arrested at another location in the same area.
This remains a breaking news event and additional updates will follow once more facts emerge.
Police officials are still reviewing specific details concerning the charges, but the arrests highlight continued vigilance regarding international spying efforts affecting Britain.