Here is Home Secretary John Reid's full statement to the Commons about the death of Russian ex-agent Alexander Litvinenko.
This statement provides a factual account of the circumstances surrounding the death of Mr Litvinenko on 23 November 2006.
There is an ongoing police investigation and for obvious reasons I am limited in what I can say to ensure the integrity of any judicial process.
I, along with the foreign secretary and health secretary, have co-ordinated the government's response on this incident.
In the late afternoon of Thursday 23 November the police confirmed with the Health Protection Agency that a significant quantity of the radioactive isotope Polonium-210 had been found in Mr Litvinenko's urine.
The material was identified following extensive tests by forensic toxicologists.
In response to this finding, police liaised closely with experts to search for any residual radioactive material at a number of locations in London.
Police have now confirmed that traces of Polonium-210 have been found at certain locations including the Itsu sushi restaurant at 167 Piccadilly, in some areas of the Millennium Hotel, Grosvenor Square and at Mr Litvinenko's home in Muswell Hill, London.
Tests are continuing at a number of locations.
The police are continuing with an extensive examination of CCTV footage to trace possible witnesses, to examine Mr Litvinenko's movements at relevant times, including when he first became ill and identify people he may have met.
Following the confirmation of the presence of Polonium-210, the Health Protection Agency investigated clinical areas at Barnet Hospital and University College Hospital.
One area in the intensive care unit remains closed at University College Hospital. All other areas at these hospitals are functioning as normal on the advice of the Health Protection Agency.
The Health Protection Agency have requested that anyone who was in the Itsu restaurant, Piccadilly, or who was in the Millennium Hotel on 1 November to contact NHS Direct where further advice is available.
In addition the chief medical officer, Professor Sir Liam Donaldson, issued advice to GPs and hospitals on the risks and clinical implications of exposure to Polonium-210.
NHS Direct have so far received approximately 500 calls relating to this incident. A small number of people have been invited to take follow-up tests as a precaution.
I emphasise that the Health Protection Agency have made clear the very precautionary nature of this invitation.
The Itsu restaurant remains closed and the Government Decontamination Service are in discussions with the owners about the clean up process.
A bar and various locations at the Millennium Hotel are currently closed to the public. Ongoing work is taking place at the hotel and at Mr Litvinenko's residence.
The coroner will decide if a post mortem will take place following advice from the Health Protection Agency. Mr Litvinenko's body is currently at a London mortuary.
The Russian ambassador was called to the Foreign Office on 24 November. He was asked to convey to the Russian authorities our expectation that they should be ready to offer all necessary cooperation to the investigation.