A POLICE investigation has been launched into allegations that Army top brass intimidated witnesses during the trial of a soldier accused of smuggling CS gas canisters into the UK.

The trial of Sergeant Michael Grundy, based at Catterick, North Yorkshire, collapsed after allegations surfaced that the Army had tried to gag soldiers whose evidence would have exposed weaknesses in the nation's defences.

Sgt Grundy told how soldiers routinely smuggled weapons into the UK to bolster the Army's depleted arsenal, and several serving soldiers were lined up to give evidence backing his case.

Now police are investigating claims that senior Army officers told potential witnesses that their careers would be destroyed if they spoke out.

Fusilier Sgt Grundy, 36, was stopped at North Shields International Ferry Terminal with 957 canisters of the gas last November.

He was charged with being concerned in the evasion of importation restrictions, but told Newcastle Crown Court that smuggling the gas from Germany was "normal procedure" for army trainers.

His trial last month was halted after Judge Beatrice Bolton ordered a police investigation into witness intimidation allegations.

And the case was back before the judge yesterday where a verdict of not guilty was recorded against Sgt Grundy.

Geoffrey Mason, prosecuting, said: "The position so far as Customs and Excise are concerned, having regard to the allegation made in the course of the trial, is it is not possible for the defendant to have a fair trial.

"Their view is that the case should not be proceeded further in the public interest and I am instructed to offer no evidence."

Judge Bolton recorded a not guilty verdict and discharged Sgt Grundy. She said the decision to drop the case was "entirely proper and fair".

She added: "It would not be possible for you to have a fair trial in future having regard to what appears to have occurred on the last occasion."

Sgt Grundy, who has served in Northern Ireland, joined the Army in 1984 and was posted to Catterick as an instructor in the 2nd Batalion of the Royal Regiment of Fusiliers.

He told the court how shortages in Army stores meant instructors had to supply their own CS gas from Germany in order to give soldiers the chemical weapons training they needed.

After his trial, defence barrister Nicholas Barker said: "It is my understanding that details that three serving soldiers who were about to give evidence on behalf of Michael Grundy's defence had been threatened with their jobs if they told the truth about the use of CS gas canisters within the Army in open court.

"Details have been passed to the police and the matter is now being investigated."

A Northumbria Police spokesman said: "We have received a complaint in relation to witness intimidation and we are now investigating the matter."

The Ministry of Defence declined to comment.