Alexander Litvinenko died of radiation sickness from polonium poisoning.
A former Russian intelligence official, he was living in exile in London, with his wife and young son, and was linked to another Russian exile, media oligarch Boris Berezovsky.
On November 1 2006 Litvinenko met two Russian intelligence officials. One of them, Andrei Lugovoi is now the chief suspect in his murder.
His widow, Marina, described the horror of watching her husband die: “He said, Marina, I feel like someone who has been poisoned with a chemical weapon. They are studying my symptoms. I told him Sasha I can’t believe what is happening to you.”
The British authorities are insisting that Russia extradite Lugovoi to stand trial for assassinating Litvinenko, but Moscow has explained that such a move is banned under its constitution. That’s what has led to tit-for-tat actions, including diplomat expulsions, and now the visa row.
Andrei Lugovoi insists he is innocent. He is now a member of the Russian parliament.
Last year, he told reporters that Litvinenko’s death was a dirty political game involving the British secret services, Litvinenko himself and Boris Berezovsky.
Berezovsky has always denied any involvement, and insists the Kremlin is out to kill him.
He says he was warned by Scotland Yard that there was a plot to kill him, which was being personally directed by President Vladimir Putin.
The diplomatic war between Britain and Russia now fuels daily battles, of which the blocking of the visas for the British Council is just another part.