Source K

Source K. In January 1942 Robert Keller, a French telephone engineer, succeeded in tapping the long-distance telephone between Paris and Hitler's headquarters in east Prussia; for some months he drew valuable intelligence from it, which he passed to Vichy by safe hand, whence in turn it reached London. (Some of Vichy's intelligence staff were ready to work with MI6.) The information of naval interest was often important. Keller made the original tap himself, with a German sentry at his elbow; all his workmen also had to operate under similar close watch, but succeeded in bluffing the sentries with technical jargon. Keller decided to extend his work to cover a second major trunk telephone line from Paris into Germany; this attempt led to disaster in December, because the Germans spotted it at once. He and several of his accomplices were arrested and deported to forced labour camps, and the source ceased to work. See also Forschungsstelle.