For more than 80 years doctors and scientists on all sides have experimented on humans to perfect weapons of mass destruction - often with fatal results. This is the terrible, and sometimes absurd, untold story. The latest episode of Dirk Pohlmanns Cold War Secrets series actually starts in the 1930s, when Japans notorious Unit 731 carried out brutal experiments on the population of recently invaded Manchuria. Whole villages and towns were deliberately infected with plague, and sufferers were dissected alive. Prisoners of war were shot and operated on without anaesthetic so army doctors could practise field surgery. In World War II Germany, concentration camp doctors like Josef Mengele selected twins and Romany prisoners for obscure medical experiments, and killed enemy prisoners in low temperature or high altitude tests, supposedly to protect their own sailors and airmen.