Porton Down Laboratories are based within Salisbury Plain, Wiltshire and has been established since 1916 as the UK's main source for the research of the use of chemicals in warfare.
The laboratory's task was to research into the use of chlorine, phosgene and mustard gas which were thought to be used in the First World War.
In the mid-1950s, work concentrated on nerve gas and tests were carried out on servicemen to determine the effects of nerve agents on humans, with one recorded death due to a sarin experiment. Ronald Maddison, aged 20, who thought he was taking part in trials to cure the common cold, was subjected to sarin being dripped on to his sleeve and later died as a result of the nerve gas agent.
Most of the work carried out at Porton Down has to date remained secret, and the UK Government have been criticised for not revealing the true extent of the research that was carried out on unwitting servicement.
