London says the attempted assassination was "almost certainly" approved by Moscow and that Russians Andrei Lugovoi
and Dmitry Kovtun were behind the killing.
and Dmitry Kovtun are the main suspects for the lethal radioactive poisoning of former KGB spy Alexander Litvinenko in London 13 years ago.
The inquiry into the murder of the dissident Russian spy Alexander Litvinenko found two Russian men - Andrei Lugovoi
and Dmitri Kovtun - had deliberately poisoned him by putting polonium-210 into his drink at a London hotel.
But Andrei Lugovoi
, 52, said it was "crazy" to think that President Vladimir Putin ordered the latest bid.
His alleged assailants, Andrei Lugovoi
and Dmitry Kovtun, are protected from extradition by the Russian constitution, and Lugovoi has been elected to the Duma, which gives him immunity from prosecution even within the Russian Federation.
The Litvinenko inquiry, headed by the former high court judge Sir Robert Owen, found two Russian men - Andrei Lugovoi
and Dmitri Kovtun - had deliberately poisoned their victim, leading to an agonising death.
Last year Andrei Lugovoi
, a parliament member aligned with Russia's nationalist LDPR party, theorized cryptocurrencies could even help Russian businesses (http://www.newsweek.com/bitcoin-technology-can-help-russia-dodge-sanctions-mp-465901) circumnavigate economic sanctions .
Users of bitcoin and other cryptocurrencies now number 200,000, with only the US, China and Germany having higher numbers, said deputy chairman of the Russian State Duma committee for security and anti-corruption, Andrei Lugovoi
21 Said The Ex-KGB Spy Alexander Litvinenko In 2006 Was Probably Murdered On Putin Order; Those Involved In His Poisoning With Polonium Were Then FSB's Head Nikolai Patrushev, And FSB Agents Andrei Lugovoi
& Dmitry Kovtun
The Government summoned the Russian ambassador and announced that the two men who allegedly carried out the killing - Andrei Lugovoi
and Dmitri Kovtun - would have their assets frozen.
Kovtun and a second Russian, Andrei Lugovoi
, are wanted by British police for allegedly poisoning Litvinenko in a London hotel on November 1, 2006 using tea laced with polonium-210, a radioactive isotope.
When Andrei Lugovoi
and Dmitri Kovtun left, Lugovoi said: "There is still tea left.