Counter-terrorism police say the 41-year-old was arrested near Gloucester as part of an investigation with US authorities and the FBI. He has not been charged.
A senior soldier in the US Army has been arrested in Gloucestershire on suspicion of offences under the National Security Act 2023 relating to Russia, British counter-terrorism police have said.
The 41-year-old man was arrested near Gloucester on Tuesday under sections 1 and 3 of the Act. Section 1 covers obtaining or disclosing protected information, and section 3 covers assisting a foreign intelligence service.
He remains in custody at a London police station. Under the Act, police can hold him for up to 14 days without charge.
Counter Terrorism Policing London said the arrest was part of an investigation carried out closely with US authorities, the US military and the FBI. Officers are searching two addresses in Gloucestershire.
Deputy Assistant Commissioner Vicki Evans, of Counter Terrorism Policing, called the arrest “significant”. “The allegations are serious and our investigation is very much ongoing,” she said.
FBI director Kash Patel said the arrest “involves allegations of espionage, which is of the utmost concern to the United States and our allies”.
Brig Gen Sean Stinchon, commanding general of US Army Counterintelligence Command, said the alleged conduct of a senior soldier “entrusted with sensitive information” was “a sobering reminder that insider threats are real and persistent”. He urged anyone who had seen something suspicious to report it.
The BBC reported that the soldier was based at Imjin Barracks in Innsworth, near Gloucester. The barracks are home to the headquarters of Nato’s Allied Rapid Reaction Corps, a multinational command that can be deployed to lead alliance forces in a crisis.
It is not known what information the investigation relates to.
The National Security Act came into force in December 2023, replacing the old Official Secrets Acts. It created new offences aimed at modern espionage, sabotage and foreign interference, including assisting a foreign intelligence service, which was not a specific crime before.
An arrest under the Act does not mean a person will be charged. If prosecutors decide to bring charges, the case will go before the courts.