VETERANS of a Nato exercise that went wrong killing five Scots-based part-time soldiers in Germany believe there has been a 40-year cover-up of what caused the tragedy.

A German police report reveals for the first time that the British military was accused of criminal negligence in Exercise Bold Guard, which was carried out over the Kiel Canal 40 years ago today.

The deaths of the 15th Scottish Parachute Battalion soldiers and a sixth soldier from the Liverpool-based 4th Battalion in 1974 was described at the time as the worst peace-time tragedy to ever befall a ­territorial unit.

Veterans say that reports surrounding official inquiries into what happened have never been released, despite requests.

Two military courts of inquiry were set up to determine why the experienced members of the ­part-time parachute force died in what should have been a routine night operation.

Tonight a service will be held at a monument in the north-west Germany village of Sehestedt in memory of victims Captain Gerald Muir, Officer Cadet James Cooper, Sergeant Richard Tomkins, Sergeant Eliot Leask, Lieutenant Corporal Brian Bett and Private Edward Beech.

Some 28 people representing both battalions, including ­veterans, flew from Edinburgh Airport yesterday to pay their respects on the 40th anniversary. They included Maureen Collison and Norma Cooper, sisters of Officer Cadet Cooper.

The men drowned when they came down too far north of their landing zone and hit the dark waters of the Kiel Canal amongst boats. One soldier was reported to have been hit by the propellor of a vessel.

They were among 15 para­troopers and four platforms that had plunged into the canal. Other soldiers were injured.

In a brief written answer to an MP's question asking about the joint Royal Air Force and Army Board of Inquiry, then Defence Secretary Roy Mason said that after an "exhaustive examination" it was decided the reason for the tragedy was that the wind at the time was stronger and more southerly than had been forecast.

Jim Carey, 67, a veteran who flew in the mission and landed safely, said he believed the full reports of what happened have been covered up because they would reveal negligence on the part of those who decided to make the drop.

Mr Carey, a retired platoon sergeant from Coatbridge, says he is one of a number of soldiers who requested details of reports and was told they would not be released. He said: "I think the German police report is evidence of either wrongdoing or negligence."

Mr Carey, who will be at tonight's service, added: "It should have been stopped, there were red flares going up. I think they were flying because the heavy drop was landing everywhere. It wasn't just down to wind we were just dropped to early."

The report reveals for the first time that German police believed there should be criminal proceedings around what happened, saying that due to a "not yet known error" the soldiers jumped too early.

The unit with 540 paratroopers and 26 platforms were dropped, but 25 soldiers and some platforms landed directly into the canal.

"During the hours after the drop there seemed to be complete chaos among the troops present at the Kiel Canal" said the report.

A criminal investigation concluded: "The result of the criminal investigations here points to the fact that German institutions, authorities or persons do not carry any responsibility for the accident." It blamed the errors on human failure by the British.

A memo by a senior public ­prosecutor in Germany urged the authorities to carry out a prosecution in the UK, if the act was an offence under British law - as it was in Germany.

The MoD was unable to provide details of reports to The Herald on request. It said it had no record of any requests made by any party for the records of the military exercise, or the court of inquiry.