The UK will not be holding a public inquiry into the murder of former Russian spy Alexander Litvinenko, who died in London in 2006 from radioactive poisoning, a British coroner said.
Robert Owen, who was assigned to hold an inquest into the death of the KGB agent, was told on Friday morning that the government had turned down his request for an inquiry.
Litvinenko, 43, died after drinking tea poisoned with a rare radioactive isotope in a London hotel, and from his deathbed he accused Russian President Vladimir Putin of ordering his murder, a charge Russia has repeatedly denied.
Owen said the British government's desire to keep intelligence evidence secret on national security grounds meant he would not be able to uncover the truth and that a full public inquiry would have a better chance of finding out who had killed Litvinenko.
In a letter to the government last month, Owen wrote, "I have formed the firm view that such an inquiry is necessary if Mr Litvinenko's death is to be properly investigated.
"For the avoidance of doubt, I should say that I regard investigation of the 'preventability' and 'Russian State responsibility' issues as being of central importance in this case."
In May, Owen had agreed to government demands to keep secret information that, if aired at an inquest, could undermine trust in the British government or "cause real harm to the UK's international relations".