The Secret Intelligence Service, MI6, has paid thousands of pounds in compensation to servicemen who were fed LSD without their consent in clandestine mind-control experiments in the 1950s. MI6 has agreed an out-of-court settlement with the men, who said they were duped into taking part in the experiments and had waited years to learn the truth. Don Webb, a former airman, said yesterday: I feel vindicated; this has been a classic cover-up for years." MI6's counterparts at the CIA also did LSD experiments on men without their knowledge to try to control their minds. Mr Webb said scientists gave him LSD at least twice in a week. He remembers a nightmarish experience when he hallucinated for a long time. He saw "walls melting, cracks appearing in people's faces ... eyes would run down cheeks, Salvador Dali-type faces ... a flower would turn into a slug". He said he had first made inquiries about the experiments in the 1960s but was "blanked by the government, which quoted the Official Secrets Act". He said he experienced flashbacks for 10 years after the experiments. "They treated us just like guinea pigs."