Russia was responsible for the assassination of Alexander Litvinenko, the European Court of Human Rights (ECHR) has ruled.
Former Russian spy Mr Litvinenko died after being poisoned with a rare radioactive substance in London in 2006.
A statement on the court’s ruling on Tuesday said: “Russia was responsible for assassination of Aleksandr Litvinenko in the UK.”
Russia has always denied any involvement in his death.
The case was brought by his widow Marina Litvinenko, who had vowed to get justice for her husband and pursue the Kremlin through the international courts.
The ruling comes as it was announced a third Russian spy – Denis Sergeev, who used the alias Sergey Fedotov while in the UK – faces charges of attempted murder over the Salisbury Novichok poisonings in 2018.
A public inquiry concluded in 2016 that the killing of Mr Litvinenko – an outspoken critic of Vladimir Putin – who died after drinking tea laced with radioactive polonium-210 – had “probably” been carried out with the approval of the Russian president.
Headed by the former high court judge Sir Robert Owen, the inquiry found two Russian men – Andrei Lugovoi and Dmitri Kovtun – had deliberately poisoned Mr Litvinenko by putting polonium-210 into his drink at a London hotel, leading to an agonising death.
It said the use of the radioactive substance – which could only have come from a nuclear reactor – was a “strong indicator” of state involvement and that the two men had probably been acting under the direction of the Russian security service the FSB – which Mr Litvinenko used to work for, as well as the KGB.
Possible motives included Mr Litvinenko’s work for British intelligence agencies after fleeing Russia, his criticism of the FSB, and his association with other Russian dissidents, while it said there was also a “personal dimension” to the antagonism between him and Mr Putin.
Mrs Litvinenko said it was a “very important day” as the findings highlighted Russia’s “brutal regime”.
She told Sky News: “It’s important that Russia takes responsibility”, adding: “We must not give up the fight against this anti-democratic regime in Russia.”
According to the statement on the European court’s ruling: “The Court found in particular that there was a strong prima facie case that, in poisoning Mr Litvinenko, Mr Lugovoi and Mr Kovtun had been acting as agents of the Russian State. It noted that the Government had failed to provide any other satisfactory and convincing explanation of the events or counter the findings of the UK inquiry.”
The court found no evidence that either man had any personal reason to kill Mr Litvinenko and would not have had access to the substance “if acting on their own behalf”.
State involvement is the “only remaining plausible explanation”, the findings said, adding that the Russia government had made “no serious attempt” to counter the findings of the UK authorities.
“The Court found it established, beyond reasonable doubt, that the assassination had been carried out by Mr Lugovoi and Mr Kovtun. The planned and complex operation involving the procurement of a rare deadly poison, the travel arrangements for the pair, and repeated and sustained attempts to administer the poison indicated that Mr Litvinenko had been the target of the operation,” the statement added.
Mr Lugovoi has reportedly branded the ruling as politically motivated and “extremely idiotic”.
According to the documents, one of the judges considering the case, Dmitry Dedov – who is Russian – expressed a “partly dissenting opinion”, expressing doubt that some of the findings had been made beyond reasonable doubt and questioning “many deficiencies in the analysis by the British inquiry and by the Court which raise reasonable doubts as to the involvement of the suspects in the poisoning and whether they were acting as agents of the State”.
Russia has been ordered by the court to pay Mrs Litvinenko 100,000 euro (£85,600) in damages and 22,500 euro (£19,300) in cost and expenses.
Mrs Litvinenko said she did not know whether she would be paid the money, but that she still hopes to bring the people responsible for her husband’s death to justice in the UK.
She later told inews: “I’m really satisfied, it’s exactly what we wanted to hear,” adding: “Of course, proper justice will end all of this. The European court ruling is important, it gives us more proof and more hope, not just in my case but other people’s cases who suffered from the Russian regime.”
Both parties have three months in which they can ask for the case to be referred before the court’s Grand Chamber, made up of the ECHR president and vice-presidents, for a final ruling.