POLICE investigating the alleged poisoning of servicemen during military research are to pass a file to the Crown Prosecution Service, it emerged yesterday.

The inquiry into experiments at Porton Down, Wiltshire, which are thought to have killed a North-East man, has turned to the scientists behind the research.

Police said they would hand files on more than one person to CPS lawyers "in due course", so they can decide whether or not to prosecute.

One servicemen, Gordon Bell, from Sunderland, said he received a letter from a detective confirming that a criminal offence was carried out during the medical experiments, which are thought to have started in 1916.

The bulk of the human guinea pigs were allegedly exposed to mustard gas, nerve agents, CS gas and LSD during the 1950s and 60s.

The letter from Detective Superintendent Gerry Luckett said: "On the face of the allegation you have made, it is apparent a criminal offence of administering a noxious substance has been committed."

Mr Luckett said there was "strong corroborative evidence" that servicemen had attended tests after seeing a notice about experiments into the common cold.

Mr Bell claims fellow RAF man Ronald Maddison, from Consett, County Durham, died in May 1953 after a nerve agent was dripped on to his arm.

Earlier this month it was revealed that a Ministry of defence epidemiological study into the issue would not start until January 2002 and was expected to last two years.