Marina Litvinenko is used to people comparing her life to a plot from a John le CarrÃ© novel.
Nevertheless, the widow of ex-KGB officer Alexander can’t help but feel shocked at the furore of the past week.
‘Perhaps it was naive,’ she says, sitting in a South Kensington cafe, the day after a pre-inquest hearing revealed that Alexander — or Sasha as she always called him — worked for MI6.
‘But I really didn’t realise it would be so big. Everywhere on TV, in the newspapers, they were saying “double agent”, “triple agent” but Sasha was not any of these things.
‘Yes, he worked for MI6 but he was not some kind of James Bond spy.
‘I understand why people are interested but for me it is very upsetting because the really important thing about the hearing was it was the first time that the Russian authorities have been cited in official documents as being responsible for Sasha’s murder. That is the really big thing.’
As the world now knows, Litvinenko, who also worked for the Russian Federal Security Service, was murdered in 2006 after the radioactive substance, Polonium-210, was allegedly put in his tea during a meeting with two ex-KGB contacts, Andrei Lugovoy and Dmitry Kovtun.
At last week’s legal review, Hugh Davies, counsel to the inquest, said assessments of confidential Government material ‘established a prima facie case as to the culpability of the Russian state in the death of Alexander Litvinenko’.
For Marina, 50, this is something of a personal victory. Reserved and gracious, she does not particularly like ‘to make a noise’, but has fought with tigress-like determination to bring her husband’s killers to justice.
She does not just mean Lugovoy and Kovtun but Vladimir Putin too — or as she puts it: ‘The murderers and their mentor.’
‘Thanks to Russia, we will never have our day in court so the inquest is our only chance to find out what happened,’ she says.
‘For the last six years it has been very difficult for me and our son Anatoly to have a normal life — the life that Sasha wanted for us.
‘I can’t just close my eyes to this — that would not be fair to Sasha or to us. I still find it unbelievable that he was killed in this way, that he had to die that slow, horrible death, and be in that pain for days.
‘But this is not just for Anatoly and me. I genuinely believe that it is important for all of us. The year Sasha was killed we had been given British citizenship.
‘We thought we were safe here but we weren’t. Sasha was poisoned with a radio-active substance on British soil. What next? It’s true that it is still shocking but now no one is surprised when a Russian is attacked in this country and that is wrong.’
Last month Alexander Perepilichny, a Russian whistleblower helping prosecutors to uncover a multi- million-pound money-laundering scam, died near his Surrey home in mysterious circumstances.
And last March, Russian banker German Gorbuntsov narrowly avoided death when he was shot by a hitman outside his home in London’s Isle of Dogs.
Marina says: ‘We cannot allow ourselves to think this is normal. It is not. But as long as Putin thinks he can do whatever he wants, this behaviour will continue.
‘People have said that by naming Russia at the inquest, we risk breaking off diplomatic relations but we have to follow this through to the end. Sasha’s murder is already like a stone between Britain and Russia. There is no communication between the two security services unless it is to do with global terrorism because of this case.’
After years of stonewalling, the Russian state has said it would like to become an ‘interested party’ in the inquest, which would give it the right to make submissions to the coroner and appoint lawyers to cross-examine witnesses.