Curiouser and curiouser: the story that becomes more mysterious by the day
1 November
Litvinenko meets former KGB bodyguard Andrei Lugovoy and an associate, Dmitry Kovtun at the Millennium Hotel in Mayfair, on the same day as meeting Italian academic Mario Scaramella at sushi bar Itsu. Later, he complains of feeling ill and is admitted to Barnet General Hospital
20 November
The former spy is moved to intensive care at University College Hospital as Scotland Yard investigate
23 November
Litvinenko dies. It is confirmed the next day he had massive amounts of polonium-210 in his body
24 November
Radioactive traces are found at the hotel and restaurant visited by Litvinenko. His family issues a statement he compiled while in hospital in which he exhorts President Vladimir Putin: "May God forgive you for what you have done". The Kremlin dismissed allegations it was involved
26 November
NHS Direct say hundreds of people have called, worried about poisoning
27 November
Mr Scaramella arrives in Britain to be interviewed as a potential witness. Home Secretary John Reid confirms the Foreign Office has told Russian authorities they were expected to "offer all necessary co-operation"
29 November
Polonium-210 found at the Mayfair office of exiled Russian billionaire Boris Berezovsky
30 November
Traces of polonium-210 have been found in 12 places, including on two BA planes at Heathrow
4 December
Nine British detective travel to Moscow as part of the investigation
1 December
Mr Scaramella tests positive for polonium-210. He is admitted to hospital but does not show symptoms of poisoning. Litvinenko's wife also tests positive for tiny amounts
6 December
Scotland Yard say they are now treating Litvinenko's death as murder. Radiation is found at the British embassy in Moscow. Mr Scaramella is discharged from hospital
7 December
Litvenko's funeral is held as tests of all seven staff working at the Millenium hotel on 1 November come back with positive traces of low levels of radiation. Russia opens an official inquiry into his murder as well as the attempted murder of Mr Kovtun, the associate he met on 1 November.
