Top KGB defector Oleg Gordievsky has died at the age of 86.
Code-named Hetman, Gordievsky was one of the most important spies of the Cold War.
Police in the south-eastern English county of Surrey said officers were called to an address in Godalming on March 4, where “an 86-year-old man was found dead at the property”.
It said counter-terrorism officers are leading the investigation, but “the death is not currently being treated as suspicious” and “there is nothing to suggest any increased risk to members of the public”.
For more than a decade Gordievsky reports gave Britain invaluable insights into the thinking of the Soviet leadership and the covert machinations of the KGB secret service.
In the early 1980s he was able to warn the West that fears among the paranoid Soviet leadership of a surprise NATO nuclear attack had brought the two sides perilously close to war, prompting US president Ronald Reagan to dial down his anti-USSR rhetoric.
His intelligence was subsequently crucial in guiding British prime minister Margaret Thatcher in her early contacts with the reformist Mikhail Gorbachev, whose ascent to power helped bring the Cold War to a close.
But in 1985, just as he had been appointed to the key post of head of the KGB residency in London, he came under suspicion as a British spy.
Summoned back to Moscow where he was drugged and interrogated, he quickly realised that his life was in danger and he needed to escape.
Using a long pre-arranged plan, a signal was relayed to his handlers at Britain’s MI6 foreign intelligence service.
A man walking past him in the street in Moscow carrying a Harrods bag and eating a Mars bar was the sign that his message had been received and the rescue was under way.
On August 2, 1985, in a daring operation personally approved by Thatcher, two MI6 officers, Raymond Asquith, great-grandson of former Liberal prime minister Herbert Asquith, and Andrew Gibbs, managed to give the Soviet surveillance the slip and smuggle their man across the border into Finland hidden in the boot of a car.
In his absence, Gordievsky was sentenced to death in Russia for treason.
Meanwhile, he established a new life, living in a safe house in London, writing a number of books and being received by Thatcher in Chequers and Reagan in the Oval Office.
In 2007, the former KGB officer was honoured by Queen Elizabeth II, being made a Companion of the Order of Saint Michael and St George (CMG) in a ceremony at Buckingham Palace.
It was, the press noted, the same honour held by the fictional superspy James Bond.