MOSCOW — A court in Moscow sentenced a former Russian intelligence officer in absentia to 25 years in prison Monday for leaking information that led to the exposure last summer of a Russian spy ring in the United States.

The Moscow District Military Court convicted Aleksandr Poteyev of treason, ruling that he had direct knowledge of the activities and whereabouts of a group of Russian sleeper agents in metropolitan Boston and New York and the suburbs of northern Virginia.

Little is known about Poteyev, a former colonel in Russia’s Foreign Intelligence Service, including his motives and his current whereabouts.