UK arrests US army member suspected of spying for Russia: police

"The 41-year-old man was arrested near Gloucester on Tuesday," London Metropolitan police said in a statement, adding that "The country to which the allegations relate is Russia."

The suspect was a member of the US Army and was being held at a London jail, police said, adding that they worked closely with US authorities on the case.

"This significant arrest and investigation is a result of close collaboration between UK and US authorities," Vicki Evans, Senior National Coordinator for Counter Terrorism Policing at the Met, was quoted as saying in the statement. "The allegations are serious and our investigation is very much ongoing."

"The alleged conduct of a senior solider, entrusted with sensitive information, is a sobering reminder that insider threats are real and persistent," Sean Stinchon, the commanding general of US Army Counterintelligence Command, said in the statement.