A military court in Moscow has found a former Russian intelligence officer guilty of high treason and desertion for his part in helping U.S. authorities arrest 10 Russian “sleeper” agents in June of last year.

The court on Monday convicted Alexander Poteyev on charges of helping expose a ring of Russian spies who had been living secretly in the United States.

The court tried Poteyev in absentia, as he is thought to have fled with his family to the United States shortly before the spies were exposed.

Prosecutors had asked for a 25-year jail sentence for Poteyev.