The double agent who betrayed 11 Russian agents to the United States was a Colonel Poteyev, not Shcherbakov, RIA-Novosti reported Monday, citing an unidentified Russian intelligence official.

“The person to blame for the betrayal is Poteyev, a colonel with the Foreign Intelligence Service who fled to the United States in spring this year,” the official said.

The official said Poteyev was under the protection of the U.S. intelligence community and posed a threat to Russian intelligence officers working in the United States.

He said Russian intelligence officials faced an enormous task protecting the identities of undercover agents.

Kommersant, which broke the story last week, identified the double agent as a Colonel Shcherbakov and said his son had worked with the Federal Drug Control Service. The service has denied employing any such person.

But on Monday an agency spokesman told Lenta.ru that Poteyev's son worked for the agency. He declined to elaborate.

President Dmitry Medvedev confirmed on Friday that the U.S. arrests of 10 Russian agents in June was the result of the defection of a senior intelligence official. The 11th suspected agent jumped bail in Cyprus in June.