Pressure rises on UK to act after naming Putin in Litvinenko death
A senior diplomat stationed at the British embassy in Moscow has revealed for the first time how Alexander Litvinenko's assassins left a trail of polonium in the building.
Paul Knott, a former Foreign Office mandarin, said he oversaw a secret sweep of the embassy by a specialist radiation detection team after the two killers, Andrei Lugovoy and Dmitry Kovtun, made a surprise visit to protest their innocence.
The sweep found traces of polonium-210 used to kill Mr Litvinenko on chairs and a table where the two men sat down.
Radiation traces were also discovered on the shelf in the security room where Lugovoy had left his mobile phone before entering the embassy.
The discoveries helped to prove that Lugovoi and Kovtun were responsible for Mr Litvinenko's murder.
Mr Knott said he also uncovered evidence of state involvement in the assassination of Litvinenko, a former Russian agent who was a British citizen at the time of his death in November 2006.
Mr Knott said the Russian ministry of transport cancelled a flight from Moscow to London shortly after the embassy had informed the authorities that the aircraft would undergo a security inspection on landing in Britain.
It was thought the plane had been used by Lugovoy and Kovtun on one of their trips to London and the Met police wanted to test the aircraft to see if traces of polonium showed up.
An inquiry into Litvinenko's death concluded last week that he was killed by Lugovoy and Kovtun and that the murder was "probably approved" by Vladimir Putin.
Mr Litvinenko had accused the Russian president of sanctioning murders and of corruption.
Mr Knott said: "Soon after they were identified as the main suspects and for reasons we never fully understood, Lugovoi and Kovtun came in to the Embassy to proclaim their innocence.
"I was asked to organise a visit by a specialist radiation detection team. I had to guide them around the Embassy in the middle of the night to avoid alarming the majority of my colleagues.
"We found traces of radiation on the chairs the suspects had sat in and on the table where Lugovoi had placed his hands. There was even a trace in the slot in the security officers' room where Lugovoi had been required to deposit his mobile phone."
Mr Knott added: "I spent the next few weeks pretending to exasperated colleagues that I had lost the key to the meeting room whilst we worked out how to preserve the furniture for evidence and make sure the room was safe again for use."
He said an "early indication" that the men were being protected by the Kremlin came when the aircraft earmarked for a radiation check suddenly "developed technical problems" a few minutes before departure. "This incident reinforced our belief that the Russian authorities were implicated in Litvinenko's assassination," said Mr Knott, who has since retired from the Foreign office and can now speak openly about what happened.
His revelations will further strengthen calls for public inquiries into the suspicious death of Alexander Peripilichnyy, 44, who collapsed and died of unknown causes, at his £3m home in Weybridge, Surrey, and the death of Boris Berezovsky, who was found hanged at his rented house in Berkshire.
Mr Peripilichnyy, who died in 2012, had fled to the UK where he handed over documents exposing a multi million pound fraud by Russian state officials.
The Litvinenko inquiry report published last week disclosed how the Metropolitan Police had thwarted an alleged assassination attempt on Berezovsky in June 2007 when officers arrested and deported Movladi Atlangeriev, a Chechen with close links to the FSB, the Russian intelligence service, who had tried to set up a meeting with the oligarch and outspoken critic of Putin.
"If the intelligence that the police are said to have received about Mr Atlangeriev was true, this event is evidence that at very much the same time of Mr Litvinenko's death, the FSB was prepared to arrange the assassination of leading opponents of the Putin regime in London," said Sir Robert Owen, chairman of the Litvinenko Inquiry.
Nikolai Patrushev, the then-head of the FSB who Sir Robert concluded probably signed off on the operation to kill Alexander Litvinenko, reputedly valued Atlangeriev's services in Chechnya so much that he presented the crime boss with an engraved pistol. Atlangeriev, who was nicknamed "Lord" or "Lenin", was kidnapped in Moscow in 2008 and is widely believed to have been murdered.