The senior British official was unequivocal. The murder of the former KGB man Alexander Litvinenko was “undeniably state-sponsored terrorism on Moscow’s part. That is the view at the highest levels of the British government”. This official had access to the latest police and intelligence findings, and he was reflecting the views of senior Home Office counter-terrorism officials, Scotland Yard detectives and others with close knowledge of the murder investigation. All confirmed last week that they believe the plot to poison Litvinenko in London last year was ordered by the Russian secret service, the FSB. After a police investigation, the Crown Prosecution Service wanted to charge Andrei Lugovoi, a former FSB officer, with the murder; and it was Moscow’s refusal to allow his extradition for trial, once the scandal had become an affair of state, that led to the expulsions. Now, however, British officials are saying that the police investigation implicates the FSB itself. They point to the estimated £4.5m cost of the radio-active polonium210 used to kill Litvinenko. They confirm it has been traced back to Russia - probably to the nuclear centre at the closed city of Sarov. They also point out that last summer the Russian parliament gave Putin the right to order the FSB to carry out assassinations of “enemies of the Russian state”. They are careful to refrain from claiming he actually ordered the killing. “Yes, the road leads to the FSB, but where the road goes once it’s inside the FSB is not something the police are really aware of,” said one of the officials.