Russia was responsible for the murder of ex-spy Alexander Litvinenko, the European Court of Human Rights (ECHR) ruled on Tuesday.

       The court said there was a strong presumption that Litvinenko had been assassinated by individuals "acting as agents of the Russian state".

       It also added the Russian government "failed to provide any other satisfactory and convincing explanation of the events", nor did it carry out "an effective domestic investigation" aimed at identifying and punishing those responsible.

       Litvinenko had worked for Soviet and Russian security services before defecting to the UK, where he was granted asylum in 2001.

       In 2006, he died in London after being poisoned with Polonium-210, a highly radioactive substance.

       A previous inquiry carried out by British authorities found the murder had been carried out by Andrey Lugovoy and Dmitriy Kovtun.