Two suspects wanted over the poisoning of Alexander Litvinenko have “no credible answer” to the scientific evidence against them, the inquiry into the spy’s killing has heard.
Mr 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 MPS wants Lugovoi and Kovtun to be tried in this country for murder but as such a trial now seems unlikely, it is important the investigation by, and the conclusions of, the MPS are made known."
Mr Horwell said that the force 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. “The MPS investigation has always had, at its central core, the science. It is the scientific evidence that condemns Lugovoi and Kovtun.
“No matter how many state honours [Russian president Vladimir] Putin may pin to Lugovoi’s chest for services to the motherland, however meteoric Lugovoi’s rise in politics has been and may become, however many times Kovtun promises to blow apart this inquiry, Lugovoi and Kovtun have no credible answer to the evidence and to the trail of polonium they left behind.”
Mr Horwell told the inquiry that the risk to the general public from the polonium will never be known.
“There can be no doubt that Alexander 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 said.
“The two attacks on Mr Litvinenko were an outrage. They led to great suffering on his part and eventually to his demise.
“We will never know how dangerous the exposure of polonium to the public at large will be and what long-term effects will be visited upon Londoners.”
Mr Horwell described those who have suggested “conspiracy theories” behind Mr Litvinenko’s death as being “driven by malice and who plainly have too much time on their hands”.
He said there was no evidence that the spy was involved in the polonium trade, and added that the suggestion he died by suicide was “a particularly spiteful and insensitive accusation” as he had “everything to live for”.
Mr Horwell went on to say the suspects’ claim that they were framed by MI6 “doesn’t bear scrutiny”.
Mr Horwell noted Lugovoi was given a medal by Mr Putin in March for services to Russia. "It obviously begs the question about what those services might have been," he said.
On the issue of why polonium was used, Mr Horwell told the hearing at the Royal Courts of Justice that “as a murder weapon it is remorseless”.
“Those who planned Litvinenko’s death did not want the cause of his death to be discovered. Polonium is a silent and normally unidentifiable agent of death.”
Mr Horwell said the suspects left behind a trail of polonium because they were unaware of its properties.
"Lugovoi and Kovtun were not the bungling assassins some have suggested," he said. "They were simply ignorant of the true qualities of the poison they carried and we suggest that ignorance was essential for those engaged to administer it covertly." – Press Association