THE family of a North-East airman, who died nearly 50 years ago after lethal nerve agent was tested on him, came a step closer to discovering the truth behind the tragedy yesterday after a High Court ruling.

Ronald Maddison, 20, of Consett, County Durham, collapsed with asphyxia after a 200mg dose of Sarin was dripped on to a patch taped to his left arm at the Porton Down research centre near Salisbury in 1953.

It is alleged that Mr Maddison believed he was taking part in experiments to find a cure for the common cold.

The original 1953 inquest was held behind closed doors and recorded a verdict of death by misadventure.

Mr Maddison's family has fought to unravel the truth ever since.

The Lord Chief Justice, Lord Woolf, sitting with Mrs Justice Hallett in London yesterday, quashed the original inquest's finding on Leading Aircraftsman Maddison and ordered a new hearing.

After the ruling, one of Mr Maddison's four surviving sisters, Lillias Crake, of Rainsworth, Nottinghamshire, expressed her relief at the result, saying she was "thrilled to bits".

Her husband, John Crake, said the tragedy had hovered over their lives for the past 49 years. "It has always been there because she and Ronald were very close," he said. "He was a very talented young man, a drummer and musician."

The coroner's counsel, Ian Burnett QC, told the High Court that the family felt "that members of the British armed forces may have been used unwittingly as human guinea pigs in tests using some of the most lethal chemical agents known to man".

Police investigated his death after looking into another case stemming from experiments carried out at Porton Down in the 1950s and 1960s.

Their findings were later relayed to the Wiltshire and Swindon Coroner, David Masters, who decided to press for a fresh inquest into Mr Maddison's death.

Lord Woolf said the High Court would make no findings as to the facts surrounding the death and the way the original inquest was carried out, but ruled it was in the public interest for a new inquest to be convened.

He said there was no dispute that the original coroner was not provided with full information about a previous, similar experiment conducted at the site.

"The previous inquest was held in camera, which meant that Mr Maddison's family never had the opportunity to hear a public investigation into the causes of his death," he said.

"Because the inquest was carried on in camera, they were kept in total ignorance of the true situation."