Fast and effective

When a prisoner arrived at any of the three camps run by the listening unit, he was immediately interrogated. It was not expected that he would give away very much information in the early years of the war. However, as Germany suffered major defeats, the interrogation process left the prisoner in no doubt that the British knew a lot about his country. Sometimes the prisoner decided that he might as well reveal all he knew. Many of the interrogations were ‘phoney’, designed to make the prisoner feel either that the British did not know very much, or that the British were stupid. An interrogator sometimes revealed only partial information, knowing that it would plant a seed in the prisoner’s mind such that he would talk about it in more detail to his cellmate afterwards. The interrogator knew that this would be recorded by the secret listeners. The interrogations worked best when used in conjunction with the bugging of the conversations. In that way, the British usually discovered what they needed to know. After being held for a few days, it was generally believed that the prisoner had talked about everything he knew. He was moved to a regular prisoner-of-war camp elsewhere in Britain where the conversations were not recorded.