The re-staged inquest into the death of a North-East serviceman in secret military chemical warfare tests has been put back to the New Year. Wiltshire and Swindon coroner David Masters is to hear the circumstances of the death of Ronald Maddison, at the Ministry of Defence's Porton Down laboratories, on Salisbury Plain, in May 1953.

The 20-year-old RAF engineer, from Consett, County Durham, died after allegedly being given a 200mg dose of the deadly nerve gas sarin.

He is thought to have been one of many servicemen and women who came forward believing they were volunteering in experiments to find a cure for the common cold, but who, instead, in some cases, were subjected to exposure to CS gas, mustard gas and hallucinogens, such as LSD.

Police have investigated the cases of hundreds of ex-service people who claim to have been among the guinea pigs in Porton Down germ warfare experiments.

The re-hearing of the Maddison inquest is seen as a test case, which may lead to criminal proceedings against some officials involved in the tests, although many have since died.

An original inquest was heard behind closed doors, "for reasons of national security", and a verdict of "misadventure" was recorded. But last year the Lord Chief Justice, Lord Woolf, who described it as, "an exceptional case", quashed the original verdict allowing a new public hearing to be staged, before a jury.

The hearing, expected to last between six and eight weeks, was initially set for a date in September.

It was cancelled and re-listed for this week (NOV 11), but the coroner has again adjourned proceedings, due to, "certain legal issues", raised with him by barristers representing some of the interested parties.

Mr Masters said all sides involved, including the MoD, the Porton Down Veterans' Association, Wiltshire's Chief Constable and lawyers for the Maddison family, have agreed to the latest adjournment.

A Wiltshire Police spokesman said a new date is being considered for early in the New Year, with the hearing to be staged at the old magistrates' court, in Trowbridge.