Russian President Vladimir Putin had probably approved the liquidation of former KGB agent Alexander Litvinenko in 2006, a British judicial investigators has concluded.
Litvinenko was poisoned with a rare radioactive isotope in a London hotel and died two weeks later. The 43-year-old was an outspoken critic of Putin.
He had said in dying testimony that he believed Putin had directly ordered his killing. The Kremlin had dismissed the allegations and has always maintained that it was part of western propaganda.
However, the British inquiry, led by judge Robert Owen, concluded that Litvinenko's killing was part of an operation directed by Russia's Federal Security Service (FSB).
"Taking full account of all the evidence and analysis available to me I find that the FSB operation to kill Litvinenko was probably approved by Mr Patrushev and also by President Putin," Owen said.
The commission said former KGB bodyguard Andrei Lugovoy and another Russian, Dmitry Kovtun, were involved in the poisoning of Litvinenko, which sent Russia-UK relations to an all-time low.
"I have concluded that there is a strong probability that when Mr Lugovoy poisoned Mr Litvinenko, he did so under the direction of the FSB. I have further concluded that Mr Kovtun was also acting under FSB direction," the judge said.
Russia's foreign ministry said The inquiry was "politicised" and was not transparent. "We regret that the purely criminal case was politicised and overshadowed the general atmosphere of bilateral relations."
Litvinenko's widow, who is in London, said in a statement: "The words my husband spoke on his deathbed when he accused Mr Putin have been proved by an English court."
23 Nov 2006 - Litvinenko dies three weeks after having green tea laced with plutonium in a London hotel
22 May 2007 - Britain's director of public prosecutions decides to charge Lugovoi, who is now a politician in Russia.
5 Jul 2007 - Russia refuses to extradite Mr Lugovoi
January 2015 - Public inquiry begins
January 21 2016 - Inquiry concludes President Putin may have ordered the killing.