Leading Aircraftman Ronald George Maddison (23 January 1933 – 6 May 1953) was a twenty-year-old Royal Air Force mechanic who was unlawfully killed as the result of exposure to nerve agents while acting as a voluntary test subject at Porton Down, in Wiltshire, England.

An even more severe reaction occurred on 27 April when one of six volunteers, a man named John Patrick Kelly, was exposed to 300 milligrams of sarin and fell into a coma but subsequently recovered.

[1] An ambulance was called and shortly afterwards Maddison complained of deafness, collapsed and began gasping for breath and the scientists injected him with atropine after they witnessed an asthma-like attack and convulsions.

[6] Maddison's father was permitted to attend the inquest but warned that he would be prosecuted under the Official Secrets Act if he informed anyone, including his family, of the circumstances surrounding his son's death.

[7] An internal court of inquiry at Porton Down found that Maddison had died because of "personal idiosyncrasy", either because he was unusually sensitive to the poison or his skin absorbed it faster than in other test subjects.

[8] A large number of samples of body parts including brain and spinal cord tissue, skin, muscle, stomach, lung, and gut were retained without his family's knowledge or permission and used over several years in other toxicology experiments.

[4][9] The Ministry of Defence applied for a judicial review to quash the unlawful killing verdict, although the government announced that whatever the outcome they would look "favourably" upon paying compensation to Maddison's family.

In February 2006 an agreement was struck within the framework of the judicial review whereby the MoD accepted the inquest verdict on the grounds that Maddison had died through "gross negligence in the planning and conduct of the experiment".