debkafile's intelligence sources report from Iran that dozens of Russian nuclear engineers, technicians and contractors are hurriedly departing Iran for home since local intelligence authorities began rounding up their compatriots as suspects of planting the Stuxnet malworm into their nuclear program.
Among them are the Russian personnel who built Iran's first nuclear reactor at Bushehr which Tehran admits has been damaged by the virus.
One of the Russian nuclear staffers, questioned in Moscow Sunday, Oct. 3 by Western sources, confirmed that many of his Russian colleagues had decided to leave with their families after team members were detained for questioning at the beginning of last week. He refused to give his name because he and his colleagues intend to return to Iran if the trouble blows over and the detainees are quickly released after questioning.
According to our sources, these detentions were the source of the announcement Saturday, Oct. 2, by Iranian Intelligence Minister Heidar Moslehi that several "nuclear spies" had been captured. "The enemy had sent electronic worms through the internet to undermine Iran's nuclear activities," he said. This was the first high-level Iranian admission that the Stuxnet virus had been planted by foreign elements to sabotage their entire nuclear program - and not just the Bushehr reactor. The comprehensive scale of the damage is attested to by the detention of Russian nuclear experts also at Natanz, Isfahan and Tehran.
Moslehi added: "We are always facing destructive activities by these espionage services and of course we have arrested a number of nuclear spies to block the enemy's destructive moves.
This statement is expected to prompt a second wave of Russian nuclear specialists to flee Iran.
The prime aim of their interrogation is to find out if Russian intelligence knowingly planted the destructive worm in Iran's nuclear facilities, possibly for under-the-counter pay, or were the unwitting carriers of equipment on order by Iran that had been previously infected.
debkafile's Western sources report that the hundreds of Russian scientists, engineers and technicians employed in Iran were responsible for installing the Siemens control systems in Iran's nuclear complex and other facilities which proved most vulnerable to the cyber attack.
They were the only foreigners with access to these heavily guarded plants. At Bushehr, for instance, the Russian personnel enjoyed full access to all its systems.   

http://www.debka.com/article/9061/