The Russian State was involved in the poisoning of Alexander Litvinenko “in one way or another”, the inquiry into the spy’s killing has heard.
Litvinenko, 43, died nearly three weeks after drinking tea laced with polonium-210 in London in November 2006.
Police concluded that the fatal dose was probably consumed during a meeting with Dmitri Kovtun and Andrei Lugovoi at a hotel in central London.
British authorities later decided that the pair - who deny involvement – should be prosecuted for murder.
Richard Horwell QC, representing the Metropolitan Police Service (MPS), told the inquiry: “The evidence suggests that the only credible explanation is that in one way or another the Russian state was involved in Litvinenko’s murder.”
The barrister said Russia had a “formidable list” of grievances against the former officer in the Federal Security Service (FSB), who fled to Britain in 2000 and became a fierce critic of President Vladimir Putin.
Litvinenko’s “most audacious and explosive” claim was that Putin was a paedophile, the inquiry heard.
Horwell also noted that Lugovoi was given a medal by the President in March for services to Russia.
“It obviously begs the question about what those services might have been,” he commented.
Mr Horwell said the Met had previously “remained silent” during the inquiry as it did not want to be seen to be having “any influence” over the evidence called.
“Our silence must now end,” he declared in his closing statement. He said the force wants Lugovoi and Kovtun to be tried in Britain for murder.
“There can be no doubt that Litvinenko was unlawfully killed and the science is such that the finger points unwaveringly at Lugovoi and Kovtun as having administered polonium to him on two occasions,” he told the hearing. As a criminal trial “seems unlikely” it is important that the conclusions of the Met’s investigation are released, Horwell said.
Addressing inquiry chairman Sir Robert Owen, he went on: “The murder of Litvinenko was intended to solve the problem that he had become but in reality it’s created a much greater one and one which this inquiry has ensured will not go away.
“We suggest that the evidence is clear. Litvinenko was murdered through the ingestion of polonium-210 on 16 October 2006 and 1 November 2006.
“Lugovoi and Kovtun poisoned him and you will decide on all of the evidence open and closed whether or not they were sponsored by the Russian State.”
Horwell said the suspects have “no credible answer” to the evidence against them.
“The MPS investigation has always had, at its central core, the science,” he explained.
“It is the scientific evidence that condemns Lugovoi and Kovtun”, he said.