MOSCOW, Nov 20: A former Russian spy fighting for his life in a London hospital after being poisoned was the target of a Kremlin-backed plot, a close friend alleged on Monday — a claim Moscow called ‘nonsense’.

The first pictures of Alexander Litvinenko released since he ingested the highly toxic thallium on Nov 1 showed him in a hospital bed, looking wan and completely bald, hooked up to medical equipment.

An effect of thallium is that its victims' hair falls out.

A Kremlin spokesman dismissed allegations that Russian security services had tried to murder the exiled former Russian agent, an outspoken critic of Russian President Vladimir Putin.

British police are investigating after Mr Litvinenko, a former colonel in Russia's Federal Security Service (FSB), successor to the KGB, said he fell ill after meeting a contact at a sushi restaurant while probing journalist Anna Politkovskaya's murder.

The hospital said Litvinenko's condition had deteriorated slightly overnight and he had been transferred to intensive care. Doctors say he has only a 50/50 chance of surviving.

Alexander Goldfarb, who helped Litvinenko defect to Britain six years ago, said the former spy was the victim of a plot directed from the heart of the Russian government.—Reuters