Ronald Maddison

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" at 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". However, the MoD did not accept that there was sufficient evidence to conclude that Maddison had not given his informed consent to take part. Following this Ronald Maddison's relatives received a total of £100,000 in compensation from the Ministry of Defence.

As a result of the investigation, and campaigning by Ronald Maddison's family, the Lord Chief Justice, Lord Woolf, sitting with Mrs Justice Hallett in the High Court quashed the original inquest verdict in November 2002. The new inquest opened on 5 May 2004 and was the longest held in England and Wales up to that time, hearing around 100 witnesses over 50 days. On 15 November 2004, the inquest jury returned the verdict that Ronald Maddison was unlawfully killed.

The Crown Prosecution Service had announced in 2003 that there was insufficient evidence to charge anyone responsible for the tests but that they would review this decision following the second inquest into Maddison's death. In June 2006, they confirmed that there would be no prosecutions.

The post mortem was carried out in Salisbury Infirmary. On 8 and 16 May 1953, an inquest was held in secret before the Wiltshire Coroner, Harold Dale, who returned a verdict of misadventure. His 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. 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.

Porton Down had been testing sarin on humans since October 1951, but the first adverse reaction was not recorded until February 1953. An even more severe reaction occurred on 27 April when one of six volunteers, a man named Kelly, was exposed to 300 milligrams of sarin and fell into a coma but subsequently recovered. This prompted a reduction in the dose used in this series of experiments to 200 mg.

Maddison's death, along with allegations that other British chemical-weapons test participants between 1939 and 1989 were not properly informed, and may have been misled about the experiments and their risks, was the subject of a police investigation, Operation Antler, in 1999–2004.

Leading Aircraftman Ronald George Maddison (23 January 1933 – 6 May 1953) was a twenty-year-old Royal Air Force engineer 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. After substantial controversy, his death was the subject of an inquest 51 years after the event.