A senior US Army soldier has been arrested in Britain on suspicion of offences linked to Russia under the National Security Act 2023, British police said, in a case being investigated jointly with US authorities.
The 41-year-old man was detained near Gloucester on November 10 and remains in custody at a London police station, according to the Metropolitan Police.
Officers are also searching two locations in Gloucestershire.
Police said the allegations relate to Russia but have not disclosed the soldier’s identity, rank or the specific conduct under investigation.
The man was arrested on suspicion of offences under Section 1 of the act, which covers obtaining or disclosing protected information, and Section 3, which concerns assisting a foreign intelligence service.
The BBC and NBC News reported that the serviceman was based at Imjin Barracks in Innsworth, near Gloucester, the headquarters of NATO’s Allied Rapid Reaction Corps.
British police have not publicly confirmed that posting.
Deputy Assistant Commissioner Vicki Evans, Britain’s senior national coordinator for Counter Terrorism Policing, said the case resulted from “close collaboration between UK and US authorities” and that the investigation remained ongoing.
FBI Director Kash Patel said the arrest involved “allegations of espionage” of serious concern to the United States and its allies.
Brigadier General Sean Stinchon, commanding general of US Army Counterintelligence Command, said the alleged conduct highlighted the continuing risk from insider threats.
The National Security Act gives police an initial detention period of up to 48 hours after an arrest under its foreign-power threat provisions.
Further detention requires judicial authorization, with Schedule 6 allowing extensions up to a maximum of 14 days from the time of arrest.
That legal framework is narrower than descriptions suggesting police can automatically hold a suspect for 14 days without charge.
Police said the investigation is not linked to any other ongoing Counter Terrorism Policing inquiry.
On Wednesday, Kremlin spokesman Dmitry Peskov denied Russian involvement, saying Moscow did not know what the arrest was connected to and had “nothing to do with it.”
No charges have been announced, and the allegations remain unproven.