This past summer's spy row between Russia and the United States was the result of a betrayal by a Russian intelligence officer, a leading business daily reported on Thursday. The scandal broke out in late June when 10 people were arrested in the United States. The spies were freed in a swap deal between Russia and the U.S. Kommersant journalists carried out an investigation and discovered that a certain Col. Shcherbakov, who had long worked for Russia's Foreign Intelligence Service (SVR), was to blame for the exposure of Russians who were working under cover. The newspaper reported that Shcherbakov's daughter has long been living in the United States but that the SVR was not too concerned about this. "It's strange that no one questioned why a person on that level has relatives abroad," an intelligence source told Kommersant. "Such things are strictly monitored even in less secret organizations." The intelligence service failed to take notice when Shcherbakov refused to accept a career promotion a year before the spy scandal - a procedure that would require him to undergo a lie detector test. This could mean that he actively cooperated with U.S. secret services at the time. Finally, no one paid attention to the fact that Shcherbakov's son, who had worked for Russia's drug watchdog Gosnarkokontrol, hastily left Russia for the United States shortly before the Russian agents were exposed. The traitor himself, said a Kommersant source in Russian state power bodies, fled the country three days prior to President Dmitry Medvedev's visit to the United States in June. The reset of Russian-U.S. relations was threatened following the espionage scandal. However, the two countries pledged the espionage row would not affect bilateral ties. Kommersant quoted a high-level Kremlin administration official as saying that Shcherbakov's fate "cannot be envied." "He will carry this with him all his life and will fear retribution every day," the paper quoted him as saying.