SS oath of silence foiled massacre inquiry: Papers show investigators were certain that officer ordered killing of up to 90 British prisoners. Stephen Ward reports

FILES released yesterday on one of the worst war crimes against British soldiers during the Second World War reveal the frustration of investigators convinced that they knew the culprit, but facing a wall of silence from an SS unit that had sworn an oath of secrecy.

Col Alexander Scotland, head of the British War Crimes Interrogation Unit in London, gave a conclusive summary in his report on the Wormhoudt massacre, in which between 80 and 90 British soldiers died, certain that Capt (later General) Wilhelm Mohnke gave the order to murder the prisoners. The colonel's report was completed in 1947 after months of questioning suspects and survivors, taking some of them back to the scene. The files, originally to be secret for 75 years, were released 17 years early by the Ministry of Defence after pressure from campaigners on behalf of survivors.

Mohnke, who has a pension of pounds 22,000 a year, was preserving his silence in Germany last night.

Scotland described how on 28 May 1940, 'approximately 80 or 90 men of the . . . Royal Warwickshire Regiment, the Cheshire Regiment and the Royal Artillery' were 'wilfully murdered' near the village of Wormhoudt, near Dunkirk, in northern France.

The British soldiers, who had mounted a fierce rearguard defence protecting troops retreating to Dunkirk, were captured, herded into a small barn, shot in groups of five at a time then finished off with hand grenades. Between 12 and 15 survived, some severely wounded, of whom four are still alive today.

The German government, under pressure from the British media, has twice, in the 1970s and late 1980s, reopened investigations into Mohnke, who was also accused of crimes later in the war against Canadian and US troops. The Germans announced last month that their investigations had failed to establish a case against Mohnke, now 83 and living in a street near Hamburg where neighbours include several former SS officers.

Scotland's report, which was strong enough to get Mohnke on the United Nations list of wanted war criminals, said: 'The German Unit which carried out the killing was the Leibstandarte SS . . . The regiment was commanded by the notorious Sepp Dietrich who has already been sentenced for crimes committed in France in 1944.'

It goes on: 'The second battalion, more closely concerned with this crime, was commanded at this time by Captain Mohnke.'

The report says Mohnke, who had taken over from Maj Ernst Schutzeck, who had been fatally injured early that morning, 'is accused of giving the order to have the British prisoners killed'.

Scotland's team may not have had enough to get a case against Mohnke to a Nuremburg trial then even if he had been found. In fact he had been taken by the Russians, who kept him until 1955, by which time war crimes trials had ended.

The files released at the Public Record Office in Kew yesterday were a frustrating pile of affidavits, the investigating officers' best shot at putting together a case. The Germans present near Wormhoudt that day in 1940 had survived the war in suprisingly high numbers, yet none gave away anything crucial. A pattern emerges from the statements: if the soldier had nothing to do with the massacre, he would pass on information he had heard about it. The closer he was to command, the less he recalled. Sepp Dietrich said he had spent the day hiding in a ditch after being wounded. Assistant Adjutant Eric Maas, at headquarters, said he had never heard about the massacre during the war.

The strongest evidence against Mohnke in the files seems to be from Cpl Oskar Senf, who described to interrogators how he had escorted some captured British prisoners: 'Captain Mohnke, commander of 5 company, who had just taken over command of the battalion, came up to us and reprimanded 2nd Lieutenant Heinrichs in our presence, because he had, contrary to orders, brought in prisoners. His words were: 'what do you mean by bringing in prisoners, contrary to orders.' '

If there had been a case at Nuremburg, it would have been that Mohnke was the officer responsible, and even if he did not give the order himself, he must have known about it and did nothing to bring the guilty men to book. As German civil law stands now, being the officer responsible would not be a crime.

Senf's statement says Heinrichs ordered him to escort the prisoners further, and when he asked the other escorts, who were all corporals or lance corporals, where they were going, he 'was told they had orders from Mohnke to shoot the prisoners'. He says he told Heinrichs he was not happy with the order. 'Heinrichs replied that we had just heard ourselves how Mohnke shouted at him.' Heinrichs died on the eastern front.

But his evidence, and others who say they think the order came from Mohnke, is second-hand (legally, 'hearsay') and not admissible.

The Rev Leslie Aitken, chaplain to the Dunkirk Veterans, who has seen most of the secret files, insists there has been no cover-up. 'I was convinced for a long time that Mohnke should be tried,' he said. 'But I showed the files to a stipendiary magistrate in Birmingham. He read them for two weeks and said that on the evidence in them, Mohnke could not be tried under the law of any civilised country.'

As well as statements from 38 former SS men, the files contain the evidence of the British survivors. None could identify Mohnke, because he was not at the barn, but at HQ. Their task was harder because none returned home immediately, and the incident was not investigated until six years later.

As in 1947, the former SS men have remained solid when re-examined by the German prosecutor. Mohnke avoided questioning by producing a doctor's note pleading a heart condition. Scotland, now dead, wrote in his memoirs sentiments which must have been echoed by the German investigators: 'I can think of no case which filled me with deeper frustration.

'Every officer present was sworn to silence. They in turn passed on the vow to the men under their command. So powerful was the fear of this oath that those who survived the war and were captured and interrogated maintained enough secrecy to baffle our experts and thwart all our hopes for a trial.'

Leading article, page 19

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