Soviet traitor and Cambridge Five spy ring member Anthony Blunt may also have passed secrets to the Nazis resulting in deaths of thousands of Allied troops, new book claims

Soviet traitor and Cambridge Five spy Anthony Blunt may have also passed secrets to the Nazis that resulted in the deaths of thousands of Allied troops, a new book has claimed.

Blunt, who died aged 75 in 1983, privately confessed to being a Soviet spy in 1964 and was publicly exposed 15 years later by Margaret Thatcher.

Now in a bombshell book, The Traitor of Arnhem, the British art historian has been accused of being the most likely candidate to be 'Josephine', who provided crucial details of an Allied operation to the Germans, and whose identity has never been revealed.

Halting the infamous Operation Garden Market, an Allied military operation that aimed to outflank the German defences along the Rhine and allow a swift advance into the heart of Germany, would have been attractive to the Russians as Stalin did not want American and British troops to land in Berlin while his army was still in action on the eastern front.

Tyrant Stalin had plans to take over Eastern Europe.

Anthony Blunt is alleged to have been a spy code-named 'Josephine' who relayed information on Operation Garden Market to the Germans in 1944, according to author Robert Verkaik

Blunt had been recruited by Stalin's security agency, The People's Commissariat for Internal Affairs in 1930s

Blunt had joined the British Army and MI5 before taking on a career as an art historian and Queen Elizabeth's curator

A letter signed by Anthony Blunt, part of the life of spies exhibition currently running at the university Library in Cambridge city centre

If accurate, Blunt's actions would have 'contributed to the deaths of tens of thousands of Allied serviceman and women and countless civilians who perished as a result of a prolonged war,' the author Robert Verkaik wrote in The Sunday Times.

He also chillingly added that the alleged mole could also be blamed for the rapes of at least a million German women by the Russians after they emerged triumphant.

Blunt graduated the prestigious Cambridge University and headed straight into the army before joining the MI5 secret services, in 1940.

At this time, he was already relaying vital information to the Russians.

The spy quickly climbed the ranks and would have been a part of the small group aware of the Operation Market Garden plans in September 1944.

The major operation saw thousands of paratroopers landing in the Nazi-occupied Netherlands to force a route into central Germany.

But the allies came face-to-face with unexpected and heavy resistance in what ended up being their final defeat of the war.

With the failure to capture the bridge over the Rhine in Arnhem the operation fell short of its main objective.

The rescue of the First Airborne Division survivors ended the operation. 

US losses totalled 3,996 dead, wounded, or missing, while British and Polish losses were 11,000 to 13,000 dead or wounded and 6,450 captured. 

German casualties numbered 7,500 to 10,000.

If accurate, Blunt's actions would have 'contributed to the deaths of tens of thousands of Allied serviceman and women and countless civilians who perished as a result of a prolonged war,' the author of The Traitor of Arnhem said

In 1951, Burgess (right) and Maclean (left) were exposed as double agents - but after being tipped off by Philby they were able to escape to Moscow

Kim Philby, a member of the Cambridge Five, was head of counter-intelligence for MI6

The five men had been graduates of Trinity College, Cambridge

A Dutch double-agent, Christiaan Lindemans, is already known to have relayed information of the operation to the Germans, but Berlin received a second, more concise briefing from a spy with the code name 'Josephine'.

In his book, Verkaik alleged that Blunt, who had been given the task of tracking down 'Josephine' a year earlier, had ultimately been investigating himself.

'Blunt had the means, the motive, and the opportunity,' the author said, claiming the spy was the only person who fit the profile of the mystery mole.

At the time, British Intelligence and military planners panicked over fears the Nazis had a mole amid their ruthless war effort.

According to Verkaik, one MI5 officer had even quoted 'Josephine's' reports as being 'the best illicit intelligence derived by the enemy' that the country had ever seen.

A year prior to the devastating Operation Garden Market, MI5 had revealed the German spy behind the elaborate 'Josephine' disguise was the lawyer Karl Heinz Kraemer, whose reports were read by Hitler himself.

Verkaik admitted that he could not wholly prove his theory behind Blunt being 'Josephine' but said 'this is more on the balance of probabilities, than beyond all reasonable doubt'.

Blunt was known as the fourth member of the Cambridge Five - a ring of Cambridge University-educated spies working for the British government who smuggled intelligence to the KGB.

Blunt's confession had stunned the Royal Family and Britain's secret services but was hushed up with the former professor being offered immunity if he admitted his role.

The deal cut by Britain’s Home Office and MI5 was so secretive even the prime minister at the time, Alec Douglas-Home, was unaware of the information.

National Archives’ documents show Douglas-Home found out about Blunt’s betrayal in November 1979, when Prime Minister Margaret Thatcher exposed Blunt in the House of Commons.

Blunt had been recruited by Stalin's security agency, The People's Commissariat for Internal Affairs in 1930s, and he later joined the British Army and MI5 before taking on a career as an art historian and Queen Elizabeth's curator.

He was stripped of his knighthood and lived as a recluse in London until his death from a heart attack. 

Who were the Cambridge Five? The Soviet double agents who rocked the British establishment

The 'Cambridge Five' spying scandal rocked the Establishment by revealing Soviet double agents at the heart of many of Britain's most important institutions.

Kim Philby, Guy Burgess, Donald Maclean and Anthony Blunt all met at the University of Cambridge, where Blunt was an academic and the other three were undergraduates.

The older man recruited the students to the Soviet cause before the Second World War - and they remained devoted to the USSR even after the start of the Cold War.

Donald Maclean (left) and Kim Philby (right) were also members of the infamous Cambridge Five spy ring

Philby was head of counter-intelligence for MI6, while Maclean was a Foreign Office official and Burgess worked for the BBC. 

Blunt was the most eminent of all, as director of the Courtauld Institute and keeper of the royal family's art collection.

In 1951, Burgess and Maclean were exposed as double agents - but after being tipped off by Philby they were able to escape to Moscow.

Despite the suspicion surrounding Philby, he avoided detection until 1963, when he too defected to the USSR.

Blunt escaped exposure for even longer - it was not until 1979, when Margaret Thatcher named him as a suspect in the House of Commons, that he confessed to his treachery and was stripped of his titles.

The 'fifth man' in the spy ring has never been definitively identified, but was named as John Cairncross by KGB defector Oleg Gordievsky.

The story of the unlikely traitors has been dramatised several times, including in John le Carré's classic book Tinker, Tailor, Soldier, Spy and a 2003 BBC series titled Cambridge Spies.

Anthony Blunt (left), the keeper of the royal family's art collection, was exposed as the fourth member of the Cambridge spy ring in 1979. The fifth member was never formally identified, although Soviet defector Oleg Gordievsky named ex-British intelligence officer John Cairncross (right) as the final link