Quiet Epsom Bank Clerk Was MI5 Wartime Spy

The MI5 agent who penetrated the ranks of Britain's wartime Nazi sympathisers has been identified as a bank clerk who lived a quiet life in Surrey.

The agent, who used the name Jack King, posed as a German agent to gain the trust of his subjects, uncover scores of would-be traitors and ensure numerous secrets were never received by the Gestapo.

Until now, King was thought to be an alias used by John Bingham, the MI5 officer who partly inspired John le Carré’s creation George Smiley.

Thanks to files released by the National Archives in Kew, however, it can now be revealed that Jack King was actually Eric Roberts - a father of three who worked in a bank and lived a quiet life with his family in Epsom, Surrey.

In February, documents had detailed how the agent Jack King was able to control the activities of hundreds of 'Fifth Columnists', effectively keeping that threat to Britain at bay.

This revelation drew speculation as to King's real identity was but Professor Christopher Andrew, author of the official history of MI5, told the Press Association that it was now clear King was actually Mr Roberts.

He spoke fluent Spanish but, with only a slight knowledge of German and having only holidayed in the country twice, he might seem an unlikely choice for risky undercover work.

Even those who worked with him at the Euston Road branch of the Westminster Bank were surprised when he was taken from them in 1940 for wartime work of 'national importance'.

One of his bosses RW Jones even wrote to MI5 asking for an explanation: "What we would like to know here is what are the particular and especial qualifications of Mr Roberts - which we have not been able to perceive - for some particular work of national military importance which would take him away from his normal military call-up in October?"

But, despite his apparent lack of qualification for the job, Mr Roberts did have a deep knowledge of the pro-Nazi groups in Britain before the war. How he gained this knowledge is not known. His ju jitsu skills may also have been handy had he ever been caught.

MI5 certainly spotted his potential, with one officer writing: "Roberts is thoroughly familiar with everything connected with the various pro-Nazi organisations in this country and (MI5 agent runner) Maxwell Knight has the highest opinion of his character and abilities."

Mr Roberts, who was 32 when war broke out in 1939, didn't let his country down either. His operation uncovered a shocking amount of support for Hitler, reported to be "certainly to scores and probably to hundreds" of people. Officers put this down to anti-semitism, with many of the traitors believing that British victory would mean victory for the Jews.

In one case Hans Kohout, an Austrian employee of a British manufacturer, handed Mr Roberts the formula of machinery that MI5 noted could, if passed to the Germans, “render our radio location system completely useless”.