 Litvinenko had obtained political asylum in Great Britain, and was an outspoken critic of Vladimir Putin and the Russian security services.It was reported that the source of the polonium had been traced to a Russian nuclear power plant, and Russia subsequently refused Britain's request to extradite ex-KGB bodyguard Andrey Lugovoy to face murder charges; Lugovoy was later elected to the Russian State Duma.Litvinenko himself blamed his murder on Putin.