Byline: By Mitya Underwood
After being promised 14 days' extra leave and pounds 15 in his back pocket in return for the testing, Ronald Maddison made a fatal decision.
On May 6, 1953, Consett-born Mr Maddison, then just 20, put his trust in military doctors and allowed them to drip 200mg of sarin B onto a piece of uniform material wrapped around his arm.
Maddison and three other servicemen were then left alone in a chamber for 30 minutes, observed and asked how they felt.
But just one hour later, the leading aircraftsman was dead.
He had become the first, and only person to die in the trials. An inquest labelled his death as misadventure, and no-one could be accountable for his death.
Half a century later, his family have finally won their long fight to get compensation from the Ministry of Defence, and uncover the truth behind one of Britain's biggest military conspiracies.
Mr Maddison is just one of thousands of servicemen believed to have been used as human guinea pigs for the testing of lethal biological and chemical agents, including nerve gas, CS gas and LSD.
Many were left with serious, long-term health problems, but others like Mr Maddison, lost their lives.
Despite such a high-profile death, it wasn't until Sunderland man, George Bell, presented a file to Wiltshire Police calling for an investigation into the testing, that the true horror of the events came to light.
In 2001, an investigation was launched into the Ministry of Defence's chemical and biological warfare site at Porton Down, in Wiltshire, where Mr Maddison was tested. Included in this long-awaited investigation was the call for a new inquiry into the death of Mr Maddison.
The original inquest into his death was held in private, for reasons of national security, and a verdict of misadventure was recorded, ruling he died of asphyxia.
Many campaigners refused to believe that the 20,000 men tested since 1916, the majority in the 1950s and 1960s, were told the full truth about their role on the experiments.
They claim the men were purposely lied to, and a result, officials were playing Russian roulette with their lives.
After George Bell contacted the police in 1999, Operation Antler was launched. Its official purpose: "To examine the issues surrounding the Service Volunteer Programme at Porton Down in relation to experiments conducted into the use of chemical and biological agents during the period 1939-1989."
Wiltshire Police put out calls to the public to track down the common cold research adverts which appealed for people to come forward and take part in the experiments.
The inquiries established a number of the participants in the research claimed to have been tricked into taking part in experiments, believing they were simply testing a common cold remedy.
The in-depth investigation lasted five years. The 13 members on the investigation panel interviewed more than 700 ex-servicemen, or their relatives who had outlived them.
The Government provided the constabulary with an additional pounds 870,000 pounds towards the costs.
In 2002, the Wiltshire Coroner's request for a new inquest in Mr Maddison's death was backed by the Attorney General and accepted. …