London: Former Russian agent Alexander Litvinenko an arch foe of President Vladimir Putin died in London on November 23 2006 after being poisoned with radioactive polonium 210.

Here is a timeline outlining the events in the affair:

2006

- October 16: Litvinenko goes to the London offices of private security company Erinys to meet with former KGB bodyguard turned businessman Andrei Lugovoi and former Red Army soldier Dmitri Kovtun.

The inquiry established that an initial radiation poisoning attempt was likely to have been made at this meeting.

- November 1: Litvinenko who had become a British citizen meets Lugovoi and Kovtun in a London hotel for tea. Litvinenko falls ill immediately afterwards and his condition steadily deteriorates.

- November 23: Litvinenko dies in a London hospital. In a letter apparently dictated on his deathbed he accuses Putin of being behind his murder while Putin responds that the death is being used for political purposes.

- November 28: Radioactive traces are found in a series of locations in London on planes used on the Moscow-London route and at the London office of exiled businessman Boris Berezovsky -- a former Putin ally turned bitter foe.

- December 6: British police say they are treating Litvinenko's death as murder.

2007

- May 22: British authorities say they want to charge Lugovoi over the poisoning and call for his extradition. He denies involvement and Russia refuses to extradite him.

- May 25: Russia's Prosecutor General Yury Chaika says that judges there will try Lugovoi for murder if Britain produces sufficient evidence.

- May 31: Lugovoi says that Litvinenko was a secret agent for the British and accuses the British secret service the Russian mafia or Berezovsky of being behind the murder. Berezovsky blames the Kremlin while Britain rebuffs Lugovoi's claim.

- June 15: Russian secret services open a spying investigation on the basis of Lugovoi's claims.

- July: Britain and Russia expel diplomats in tit for tat moves.

- September 17: Lugovoi is named a candidate for the far-right nationalist LDPR for December's elections in Russia and says he wants to run for the presidency in 2008.

- October 27: British newspaper the Daily Mail reports that Litvinenko was working for the British secret services citing unnamed diplomatic and intelligence sources.

- November 1: Lugovoi accuses the British secret services of trying to hide the truth about the Litvinenko affair and again protests his innocence.

Litvinenko's widow Marina accuses Putin of blocking investigations into her husband's death.

2013

June: A coroner delays a judicial inquest into the death ruling that a public inquiry sanctioned by the government would be more appropriate.

July: The British government rules out a public inquiry.

2014

January: Marina Litvinenko applies to London's High Court to force the government to launch a public inquiry.

February 11: The High Court rules that the government was wrong to deny a public inquiry.

July 22: Interior minister Theresa May announces a public inquiry days after the crash of Malaysia airlines Flight 17 over eastern Ukraine blamed on Russian separatists.

The inquiry is authorised to hear intelligence material not previously allowed in the inquest.

2015-2016

The public inquiry concludes on January 21 2016 that the Russian state "probably" approved Litvinenko's murder and that it was carried out by Lugovoi and his ally Kovtun.

AFP