Russia honoured Cold War-era Soviet double agent George Blake today at a special gala marking his 85th birthday.
Mr Blake, reviled in Britain as a traitor to crown and country, said he had lived a "full and happy life". He turned 85 yesterday.
He was a British secret agent from 1944 until 1961, when he was jailed for 42 years after pleading guilty to spying for the Soviet Union. He escaped from prison in London in 1966 and has lived in Moscow since.
He left three children behind in Britain when he escaped and started a new family in Moscow.
Russia's SVR foreign intelligence service, successor to the mighty First Chief Directorate of the Soviet KGB secret police, feted Mr Blake at a special gala at its headquarters this evening, the SVR said.
SVR director Mikhail Fradkov decorated Mr Blake with the Friendship Order and read out telegrams from Russia's leadership.
"The importance of the information supplied by Blake can hardly be overestimated," SVR spokesman Sergei Ivanov said.
In 1953 Mr Blake tipped off the Soviet intelligence of plans by British and US secret services to build a tunnel into the Soviet-occupied zone of Berlin to tap into landline communication of the Soviet Army headquarters.
The Soviets unearthed the tunnel in 1956 after it had been in operation for almost a year. But only after Mr Blake's arrest in 1961 did Western intelligence officials realise Moscow had used its knowledge of the tunnel to misinform them.
"It is namely thanks to Blake that the Soviet Union avoided very serious military and political damage which the United States and Great Britain could have inflicted on it, should they have succeeded in such a large-scale operation now widely known as 'The Berlin Tunnel'," Mr Ivanov said.
Relations between Britain and Russia have come under strain after Moscow refused a request to extradite the chief suspect in the killing of former Russian agent Alexander Litvinenko in London a year ago.