The British government has announced a public inquiry into the death of Alexander Litvinenko, the Russian dissident who was poisoned in London with radioactive tea in 2006.
Home Secretary Theresa May, the interior minister, made the announcement to parliament, adding: "I very much hope that this inquiry will be of some comfort to his widow."
The decision, announced by Home Secretary Theresa May on Tuesday, means investigators can look into whether the Russian state played a role in the death of Litvinenko.
The announcement of the inquiry comes at a time of rising tensions with Russia over its role in Ukraine.
Litvinenko accused Russian President Vladimir Putin of ordering his murder from his deathbed after he was poisoned in London in 2006. The ex-KGB agent died after drinking tea poisoned with a rare radioactive isotope.
A coroner's inquest, the normal method of examining an unexplained death in the UK, has been barred from considering secret evidence about the possible role of the Russian state.
Until now, the UK government has declined to conduct a full scale inquiry, long sought by Litvinenko's widow, Marina, leading to accusations it wanted to appease the Kremlin which has always denied any involvement in the death.
Britain's High Court ruled earlier this year that the government had to reconsider its decision not to hold an inquiry.