Friends and family dismissed claims that Alexander Litvinenko, the Russian ex-spy poisoned in a London hotel, was an MI6 agent paid £2,000 a month when he was murdered.
Reports suggesting that Mr Litvinenko was actually working for British intelligence could provide the key to his unusual killing. Investigators believe his death resulted in a diplomatic row between London and Moscow after Russia refused to extradite Andrei Lugovoy, described as the prime suspect in Mr Litvinenko's murder. The refusal then led to the expulsion of four Russian diplomats from London. Days later Moscow responded in a tit-for-tat expulsion of four UK diplomats from Russia.
But the claim was denied by the dead man's wife, Marina. Mrs Litvinenko, who is in Portugal to lobby European leaders to put pressure on Russia's President Vladimir Putin to extradite Mr Lugovoy, said her husband did not work for MI6.
Former double agent Oleg Gordievsky, a friend of Mr Litvinenko, described his being paid regularly by MI6 as "total nonsense". "I spoke with him heart-to-heart, brain-to-brain and eye-to-eye on many occasions and he told me about every interesting encounter he had, so I know this was not the case," Mr Gordievsky said.
"He was invited to MI6 on two occasions to provide education on how the Russians worked but he was not given any operational tasks. He was paid £800 for each of these lectures, but that is all. He believed if he impressed MI6 he would one day be able to ask them for a job which would later give him a pension. But MI6 told him they were not going to employ him any more and this deepened his depression as this had been his secret plan."
Mr Gordievsky believes it was financial troubles that led to Mr Litvinenko's murder. "His salary from Boris Berezovsky decreased from £8,000 to £1,200 a month. At that time Lugovoy started offering him nice work and Sasha [Litvinenko] didn't realise that Lugovoy was a spy. These discussions about work were all a ploy by Lugovoy: he had only one idea and that was to create a situation to kill Litvinenko. He was working on behalf of the KGB with clear instructions from Putin to kill Litvinenko at any price."
Martin Sixsmith, the author of a book on Mr Litvinenko's murder, said: " My understanding is when Litvinenko came here he was financed entirely by Berezovsky but, as his use dwindled, Berezovsky cut his allowance, which threw him into a panic. I understand he then met M16 for which he received one-off payments. He also started looking for security work in Russia and this was played on by Lugovoy and Kovtun. They lured him into a number of discussions and got him to act as their agent with private intelligence and security services. This led him into the lion's den and the rest of the story we know.
“It was not a long-term relationship with MI6, but the claim permits Lugovoy to say Litvinenko was working for the British and they killed him.”