THE Government plans to challenge the verdict of an inquest that ruled a County Durham airman was unlawfully killed more than 50 years ago.

Leading Aircraftman Ronald Maddison, an RAF technician from Consett, died aged 20 during secret nerve gas experiments at the Porton Down chemical warfare testing facility, in Wiltshire.

His family has battled since 1953 to find out how he died, and last month thought their fight for justice was over when a second inquest returned a verdict of unlawful killing.

They now plan to sue the Ministry of Defence (MoD) for compensation in a case that could pave the way for hundreds of other servicemen who were subjected to experiments at the site between 1939 and 1989.

The MoD has apologised to Mr Maddison's family and said it would look favourably upon any bid for compensation, then added that it would be seeking a judicial review to overturn the inquest ruling.

Mr Maddison died after having drops of sarin dabbed on his arm.

Winston Churchill's government ordered the initial inquest into Mr Maddison's death, which reached a verdict of misadventure, to be held in secret.

After years of campaigning by the family, an inquiry was launched by Wiltshire Police in 1999, and in 2002, Lord Chief Justice Woolf granted permission for a second inquest, which began last May.

A statement from the family's solicitor, Alan Care, said: "We are pleased that the MoD have at long last apologised to the Maddison family - following our two letters to the Prime Minister requesting his personal apology - and that the MoD will favourably consider compensation given an acknowledgement of negligence in causing the death of Ronald Maddison.

"However, it is with absolute astonishment that we see that the MoD intend to challenge by way of judicial review the inquest verdict. After all, the jury heard more than 60 days ofevidence from over 100 witnesses and the jury's unlawful killing verdict was unanimous."