Ferguson Smith - Telegraph At the same time Ferguson Smith and two colleagues went to Ruislip to see the Krogers and ask them to accompany them to Scotland Yard for questioning. Before leaving, Mrs Kroger asked to be allowed to stoke the boiler. When Smith, a veteran spycatcher, checked her handbag, it was found to contain microdots, reproducing secret documents in miniature. These, it transpired, were hidden in antiquarian books provided by Kroger to Lonsdale, who sent them with letters to his wife in the Soviet Union. In the Kroger bungalow the police found large sums of cash and a mass of spying equipment, including fake passports, photographic material, code pads and a long-range transmitter linked to Moscow. It was the espionage coup of the decade and the crowning moment of Smith's career in Special Branch, which he had joined in 1936 and went on to lead from 1966 to 1972. Ferguson George Donaldson Smith (known as Ferg or Fergie) was born in Aberdeen on October 5 1914 into a family of wholesale grocers who claimed to have introduced Robertson's marmalade to the breakfast tables of northern Scotland. He was an outstanding sportsman at Aberdeen grammar school, where he was head of school and captain of rugby and cricket. With the Cairngorms just a long bike ride away, he developed a lifelong love of mountains. Apart from 18 months as a constable on the beat and his wartime service, he spent his whole working life in Special Branch. His mother disapproved of his career choice, regarding it as "a thorough waste of a good education." Smith enlisted into the RAF volunteer reserve in July 1941 and trained as a navigator in Canada, where he was commissioned. On his return to Britain, and after further training, in August 1943 he joined No 101 Squadron flying Lancasters from Ludford Magna near Lincoln. A month later No 101 crews began to fly specially modified Lancasters fitted with top-secret radio jamming equipment. An additional "Special Operator" joined each crew to work this equipment, which located and jammed German fighter control's broadcasts; occasionally, the German-speaking operator posed as a controller to spread disinformation. During the winter of 1943-44, No 101 crews fought in the Battle of Berlin, suffering a high number of casualties. In January 1944 Smith and his crew were approaching Berlin when their aircraft was attacked by a German nightfighter and badly damaged. Smith sustained severe injuries, being wounded in the back, the chest and the leg, but refrained from reporting his injuries, instead working heroically to rescue the two gunners who were trapped in their turrets. Not until it was apparent that both men were beyond assistance did Smith relax his efforts. Meanwhile the pilot pressed on to the target which the crew bombed successfully before making the long and hazardous return trip. Despite his wounds, Smith remained at his post and skillfully navigated the defenceless Lancaster back to base where the pilot made an emergency landing. Both men were awarded an immediate DFC, the citation for Smith concluding that "his courage, fortitude and determination were worthy of the highest praise." Smith spent several months recovering before returning to No 101, where he flew on operations for another year. With its unique role of electronic jamming, and with its aircraft carrying aerials that made them uncomfortably conspicuous targets for the Luftwaffe, No 101 suffered the highest casualty rate of any RAF squadron in the war. In April 1945 Smith was awarded a Bar to his DFC. After a period in Transport Command, Smith was released from the service in February 1946 as a flight lieutenant. On discharge he returned to Scotland Yard, where his linguistic skills - he spoke fluent German, French and Russian - were of particular value to Special Branch during the Cold War. His service there brought him into contact with many famous figures as well as spies, including Oswald Mosley, the British fascist leader, the explorer Laurens van der Post, and the star of the wartime Double Cross, Eddie Chapman (better know as Agent Zigzag). Smith was protection officer to the Duke of Windsor on his infrequent visits to London after the Abdication, once turning down a gratuity from the former king (saying simply: "I don't take tips.") He kept a close eye on the British Communist Party, whose annual meeting was regularly monitored by the Branch, and went out to Ghana to supervise security for Kwame Nkrumah at the country's independence celebrations. In September 1962 Smith (by then a detective superintendent) was the lead investigator into the John Vassall case. Vassall, a homosexual who had been blackmailed into becoming a spy while Naval attaché at the British embassy in Moscow during the 1950s, was then assistant to Tam Galbraith, a Civil Lord of the Admiralty. He had provided the Soviets with thousands of classified documents until 1961, when he was identified by a Soviet defector. Smith helped verify this allegation, and in October 1962 Vassall was convicted and sentenced to 18 years imprisonment. In 1966 Smith was appointed to lead Special Branch as Deputy Assistant Commissioner. By then there were over 300 Special Branch officers at Scotland Yard and a unit in each of the 42 regional forces. Their main attention at that time was on the activities of the Soviet Union and the Eastern bloc countries and, increasingly from the end of the 1960s, the IRA, as well as the protection of visiting VIPs. On his retirement in 1972 Smith was appointed CVO and lived quietly in Surrey with his wife, reading poetry and enjoying the countryside, never moving from the house they had bought in 1952. His peace was only disturbed by two three-month security tours in the Seychelles for the Foreign Office, for which he persuaded his wife to overcome her fear of aeroplanes and accompany him on the only flights of her life. Ferguson Smith married, in 1944, Margaret (Rita) Murphy. She died in 2003. A son and daughter survive him. Ferguson Smith, born October 5 1914, died September 15 2013