Graham Russell Mitchell  Graham Russell Mitchell OBE, CB (1905–1984), was an officer of MI5, the British Security Service, between 1939 and 1963, serving as its deputy director general between 1956 and 1963. In 1963 Roger Hollis, the MI5 director general, authorised the secret investigation of Mitchell following suspicions within the Secret Intelligence Service MI6 that he was a Soviet agent. It is now thought unlikely that Mitchell ever was a "mole". Mitchell was an International Master of correspondence chess who represented Great Britain. Graham Mitchell, the eldest child of Alfred Sherrington Mitchell, a captain in the Royal Warwickshire Regiment, and Sibyl Gemma Mitchell, née Heathcote, was born on 4 November 1905 in Kenilworth, Warwickshire. He attended Winchester College, and later Magdalen College, Oxford to read politics, philosophy, and economics, earning his degree. In 1934, he married Eleonora Patricia Robertson (1909–1993), daughter of James Marshall Robertson, and the couple had two children. As a child he had contracted poliomyelitis, which left him with a pronounced limp, but he nevertheless went on to become an accomplished golfer. He sailed for Oxford University. In lawn tennis, he was a partner in the men's doubles winning team of the Queen's Club Championships in 1930. He represented Oxford University at over-the-board chess. He later represented Great Britain at correspondence chess. He placed fifth in the first International Correspondence Chess Federation (ICCF) World Championship tournament (1950–1953), and inflicted the only defeat on the eventual champion, Australian Cecil Purdy. From that result, scoring (+6 =4 -3), he earned the title of International Master of correspondence chess (IMC), in 1953. After graduation in 1927, Mitchell was briefly a journalist for the "Illustrated London News". In the mid-1930s, he joined the research department of Conservative Central Office, led by Sir George Joseph Ball; Mitchell served as a statistician.; The "research department" was actually an intelligence service which had infiltrated Labour Party Headquarters. Unfit for military service because of his polio, he joined the MI5 in November 1939, two months after the start of World War II, upon Ball's recommendation. Chapman Pincher and Nigel West both suggest that it was Ball's influence that enabled Mitchell to be accepted into that organisation; Ball himself had been in MI5 until 1927, and was later appointed to the highly secret home defence security executive.