UK police questioned on Wednesday a 41-year-old US soldier assigned to NATO over suspected espionage for Russia. The questioning followed his arrest in a joint investigation with American military and law enforcement agencies.
The soldier was detained near Gloucester, southwest England, on suspicion of violating national security laws and taken to a London police station, police said.
A senior NATO military official confirmed he was assigned to the alliance's Allied Rapid Reaction Corps (ARRC), a high-readiness multinational headquarters led by the British Army.
Vicki Evans, senior national coordinator for UK Counter Terrorism Policing, said the arrest followed close cooperation between British and US authorities.
"The allegations are serious and our investigation is very much ongoing," she said.
FBI Director Kash Patel described the arrest as significant, saying espionage allegations were of the utmost concern to the US and its allies.
Investigation and security concerns
Police said searches were under way at two locations in Gloucestershire. The soldier was arrested under laws covering the disclosure of protected information and assistance to a foreign intelligence service. He can be held without charge for up to 14 days.
Sean Stinchon, commanding general of US Army Counterintelligence Command, called the alleged actions of the senior soldier, who had access to sensitive information, a "sobering reminder" that insider threats remained real and persistent.
Police said the investigation was not linked to any other ongoing inquiries.
Numerous arrests since the war began
The case comes amid heightened tensions between Russia and European countries following Moscow's 2022 full-scale invasion of Ukraine. Western governments have repeatedly accused Russia of espionage and efforts to undermine support for Kiev.
In September, a British man appeared in court over allegations that he was preparing to sabotage drone manufacturing sites on behalf of Russian military intelligence.
Last year, another British man was jailed for seven years for attempting to spy for Russia.
Several other men were also imprisoned for setting fire to a warehouse storing supplies for Ukraine after Russia's Wagner group recruited the alleged organiser of the attack.
