Litvinenko's death: the toxic legacy

It is a year since the death of the Russian dissident, an event which changed the course of diplomatic history but which remains as mysterious as ever

This morning the four people closest to the poisoned Russian exile, Alexander Litvinenko, will make a pilgrimage to commemorate the first anniversary of his death. They will stand on the spot outside University College Hospital that became so familiar to British television viewers last autumn, and read out the testament Litvinenko dictated on his death-bed, implicating President Vladimir Putin in his death.

His widow, Marina, is expected to be there, as is Boris Berezovsky, the Russian billionaire-in-exile who underwrote the Litvinenko family's flight from Russia and set up the Litvinenko Justice Foundation in Alexander's memory. Alex Goldfarb, whose American-accented bulletins from outside the hospital relayed the symptoms of the exile's mysterious illness and inexorable decline, will be present and the dead man's father, Walter Litvinenko, who will have flown in one more time from Russia.

This mournful reunion – to which reporters and cameras are invited – will be a shocking reminder of how one outspoken enemy of the Putin administration met his death in a country, and a city, he had believed was safe. Addressing Mr Putin directly, his phrases are resonant. "You may succeed in silencing one man, but the howl of protest from around the world will reverberate, Mr Putin, in your ears for the rest of your life."

But the re-reading of Litvinenko's bitter J'accuse will also underline both how little real progress has actually been made in resolving the killing since then and the extent of the fall-out for relations between Britain and Russia.

It was only after Litvinenko's death that polonium-210 was identified for certain as the poison. There followed an extraordinary international scramble to trace the route of the radiation – and so, it was hoped, find the culprit. Detectives scoured London; they went to Hamburg and Moscow. Hundreds of airline passengers were contacted and tested for radiation exposure. Half a dozen planes were recalled from distant parts and minutely examined for contamination. And all the while, the net seemed to be closing in around Andrei Lugovoi and Dmitry Kovtun, Litvinenko's two Russian companions for tea at the Millennium Hotel on 1 November.

This did not, however, prevent alternative theories about Litvinenko's death from multiplying. There was the obvious one, set out in Litvinenko's last testament, according to which Mr Putin had ordered the former policeman's death for treachery. In support of that was the difficulty of obtaining polonium-210 outside a couple of state laboratories.

Russia had also recently passed a new law that in effect permitted Russian agents to kill enemies of the motherland.

But there were other theories, too. According to one, Litvinenko had become involved in unsavoury business dealings. He had been killed to order, but not necessarily by the Kremlin. Polonium-210 might be hard to obtain, but the security of Russia's laboratories had long been regarded as suspect.

Variants had Mr Berezovsky becoming disenchanted with a protégé who might have turned awkward, or the British secret services piqued by Litvinenko's unreliability, or reluctance to operate for them. The most far-fetched theory of all was that Litvinenko had poisoned himself – either deliberately, in despair at his lack of future in exile, or accidentally as a result of a black-market radiation deal gone wrong.

Then six months after Litvinenko's death, on 22 May, it seemed that the alternative theories might be laid to rest. The director of public prosecutions, Sir Ken Macdonald, announced that there was enough evidence to charge the former KGB officer Mr Lugovoi with murder. Six weeks later, Russia formally rejected a request for Mr Lugovoi's extradition. Ten days afterwards, Britain expressed its frustration by expelling four Russian diplomats, and Russia retaliated, one for one.

This is pretty much how things have remained: Russia adamant that its constitution rules out the extradition of its citizens, and Britain – generally a stickler for legal niceties – accusing Russia of obstruction. British officials are still furious that a British citizen (Litvinenko had obtained his new passport days before he fell ill) was killed in London and hints at the risk it perceives to other exiles from Russian secret agents.

From the safety of Moscow, Mr Lugovoi spins tales – not all of them implausible – about how British intelligence tried to recruit him and how Litvinenko was in the pay of MI6.

None of this makes Mr Lugovoi's guilt or innocence more likely. Even if he, or Mr Kovtun, were involved, the question remains: were they agents of the Kremlin or of some other group? Are we talking principle, here, or money? All that can be said with any confidence is that diplomatic relations between Britain and Russia are glacial, and likely to remain so for some time.

Where are they now?

MarinaLitvinenko

Marina Litvinenko, widow of Alexander, lives in London with their son, 13. Campaigning for her husband's presumed killer to be extradited.

Boris Berezovsky

Russian oligarch and patron of Litvinenko. Still lives in London, but his calls for the overthrow of Mr Putin have been less frequent. He was tried in absentia in Russia for embezzlement over the privatisation of the national airline (verdict postponed until 29 November). Was also wanted in Brazil for money-laundering, but has announced a $1bn investment in Brazil's economy.

Alex Goldfarb

Smooth-talking former journalist and publicist is still employed by Berezovsky, mainly in connection with the Litvinenko Justice Foundation, and has co-authored a book with Marina Litvinenko.

Andrei Lugovoi

Russian businessman, former KGB agent and chief suspect in the murder: he lives in Moscow, periodically turns up in front of a television camera to protest his innocence, and is standing for the Russian parliament in elections on 2 December – for the extreme right-wing party of Vladimir Zhirinovsky. Success would ensure him immunity from prosecution in Russia.

Vladimir Putin

Russian President and former head of the KGB: he was accused by Litvinenko in a bitter deathbed statement of having ordered his murder, an accusation Mr Putin categorically denies.

Norberto Andrade

The barman who served Litvinenko and received a dose of radiation himself. The bar has just reopened after a year's closure for decontamination.