RUSSIA was responsible for the assassination of Alexander Litvinenko, the European Court of Human Rights has ruled.

The former Russian agent died after being poisoned with polonium in a London hotel in 2006.

The 43-year-old worked for the Federal Security Service (FSB), the successor to the KGB, before fleeing to Britain, where he was employed by MI6.

Releasing a statement on its ruling, the European Court of Human Rights (ECHR) said: "Russia was responsible for the assassination of Aleksandr Litvinenko in the UK."

Vladimir Putin is long suspected to have personally signed off on the murder, but this is denied by the Kremlin. 

Litvinenko died three weeks after drinking green tea laced with radioactive poison at the Millennium Hotel.

Before he died, Litvinenko said: "You may succeed in silencing one man but the howl of protest from around the world, Mr. Putin, will reverberate in your ears for the rest of your life."

His widow, Maria Litvinenko, has claimed that the Kremlin was behind the killing, but she did not accuse Putin of personally ordering the act.

In 2016, a UK inquiry by Sir Robert Owen concluded that Putin probably signed off on a Russian intelligence operation to murder Litvinenko.

The investigation also concluded former KGB bodyguard Andrei Lugovoy and another Russian, Dmitry Kovtun, carried out the killing as part of an operation most likely directed by the FSB.

The ECHR added: "The Court found in particular that there was a strong prima facie case that, in poisoning Mr Litvinenko, Mr Lugovoi and Mr Kovtun had been acting as agents of the Russian State."