By Michael Holden
LONDON (Reuters) - The coroner tasked with overseeing an inquest into the murder of former Russian spy Alexander Litvinenko called for the British government to hold a public inquiry into the death after he concluded evidence would be kept secret from his own hearing.
Litvinenko, 43, died after drinking polonium-210, a radioactive isotope, that had been slipped into his tea at a London hotel in 2006. In a deathbed statement, he accused Russian President Vladimir Putin of ordering his murder, a claim Russia has denied.
Last month, Robert Owen, a senior judge acting as coroner, decided that some crucial evidence relating to the possible involvement of the Russian state in Litvinenko's death and whether it could have been prevented would be kept secret from his pending inquest.
His ruling followed a request from British Foreign Secretary William Hague to withhold information that could undermine trust in the British government or "cause real harm to the UK's international relations".
At the time, Owen said this meant he would no longer be able to hold a "full, fair and fearless inquiry" into the death and that it would render its verdict potentially misleading or unfair.
Previous pre-inquest hearings had been told the British government possessed information which established "a prima facie case" that Russia was behind the killing.
Litvinenko's death plunged relations between London and Moscow to a post-Cold War low, but Prime Minister David Cameron has made great efforts to improve ties since he came to power in 2010.
Litvinenko's family have argued that the British government wanted to cover up his work for its MI6 intelligence service and evidence of Russian involvement, to protect lucrative trade deals.
The former KGB agent's widow Maria said she was "utterly dismayed" by Owen's ruling last month that some evidence would have to be kept secret, which she described as a political fix to help Russia and Britain rebuild their relations.
Owen has now written to Britain's Justice Secretary Chris Grayling, asking him to order a public inquiry which could examine all the evidence, including information which the government would not wish to be made public.
"We will carefully consider this request," a government spokeswoman said.
(editing by Stephen Addison)