- Douglas was an amateur radio enthusiast and was a Chief Technician in Signals Intelligence (SIGINT) who had been in the RAF since 1949.
It appears that Douglas's marriage was in trouble and he took to drink as his marriage broke up in money worries.
When he was arrested on 13 September 1968 he was stationed at RAF Digby in Lincolnshire, an extremely sensitive RAF signals unit. His detection came about from both technical and physical surveillance on the Soviet Consulate in Kensington Palace Gardens.
Douglas Britten had been recruited in 1962 by a man known to him simply as YURI. The Russian had approached him while he was strolling through the Science Museum in South Kensington, and had addressed him as 'Golf Three Kilo Foxtrot Lima', his amateur call-sign. It was later assumed that the Soviets had made a study of radio hams who were servicemen and had selected Britten as a target. When the conversation turned to Britten's job, YURI asked him to obtain a wireless transmitter known as the 1154. In fact this set was considered obsolete by the RAF and it was generally available to radio enthusiasts on the open market. YURI pretended not to know this and paid Britten well for this piece of equipment. When Britten was posted to Cyprus shortly after this encounter, the Russians appointed a local case officer who had the RAF technician photographed receiving money in exchange for local gossip. Thereafter Douglas was constantly blackmailed. When the first hand-over is accompanied by a payment there is thereafter an implicit threat of blackmail. Britten's first transactions were motivated by financial gain. Forever afterwards there was always the risk of exposure.
In October 1966 Douglas was transferred back to England and came under the control of a Soviet intelligence officer, later identified as Alexsandr Ivanovitch Borisenko, who had been First Secretary at the Embassy since May 1966. In January the following year Douglas held a meeting with Borisenko at Arnos Grove station, in north London. Pressure was reapplied on Douglas and he continued to supply the Russians until February 1968, when he was photographed hand-delivering a message to the Consulate, after his case officer had failed to turn up for a rendezvous.
During the Cold War, the KGB developed several disguised cameras, including one that looked just like a small leather pocket wallet - the edge of it was rolled against a document to expose the film. Douglas was blackmailed by the KGB into using one of these to photograph material at RAF Digby.
At his trial at the Old Bailey on 4 November 1968 before the Lord Chief Justice, Lord Parker, Douglas Britten pleaded guilty to offences under Section 1 of the Official Secrets Act, 1911, and was sentenced to twenty-one years' imprisonment. He had been subject to the Positive Vetting procedure but, as it was later pointed out, this merely screened individual candidates, it did not detect traitors. Douglas Britten's activities had been highly damaging and, in military terms, were of much greater significance than previous post-war cases. Nevertheless, Douglas fully recognized the extent of his treachery and co-operated, both with the RAF police investigators who had arrested him, and the Security Service. He was 32 years of age when sentenced.
The Douglas Britten case attracted only the minimum of publicity because of the defendant's plea of guilty.
Of those exposed for spying, Douglas Britten had done by far the most damage and his arrest had helped to reduce the leakage of the RAF's signals intelligence secrets. It was only in the summer of 1982 that MI5 belatedly learned of a second Soviet source active in the same period, Geoffrey Prime, who had also been disposing of equally sensitive information from Government Communications Headquarters at Cheltenham.