A newspaper in Moscow on Thursday named a top Russian double agent as the spy who betrayed his country to help the Americans break up an espionage ring.
The Kommersant daily names Colonel Shcherbakov, a senior official in Russia’s foreign intelligence agency, as having cooperated with the CIA.
Ten Russian sleeper agents in the US were arrested and sent back home in June.
Prime Minister Vladmir Putin has not commented on the identity of the mole but has vowed that the spy who double-crossed the Kremlin would be severely punished.
“We know that traitors always meet a nasty end,” he said in June.
The spook swap was the biggest US-Russian spy scandal since the end of the Cold War.
Colonel Shcherbakov is believed to have fled to the United States.