Russia's secret services have abandoned the Soviet-era practice of killing traitors, says Prime Minister Vladimir Putin.
He was answering questions on a live phone-in session on state TV and radio.
Asked if he ever had ordered special services to kill traitors, Putin said that such practices ended with the Soviet Union.
He also said that the "animal" who betrayed the 10 Russian sleeper spies who were arrested in the United States this summer will not live happily.
Putin has met and sang patriotic songs with the 10 agents who returned home after a spy swap shortly after their arrest, and he again praised them today.
He referred to a Russian intelligence officer suspected of betraying them as a "swine".
Britain has been seeking the extradition of Andrei Lugovoi suspected in the murder of dissident ex-KGB agent Alexander Litvinenko in London in 2006. Mr Litvinenko was poisoned with radioactive polonium.
British officials have claimed the murder was carried out with the backing of the Russian state.