A retired lighting technician who served at a Second World War death camp where 1,400 Jews were executed could be the next Nazi tried for mass murder, it has emerged .

Helmuth Leif Rasmussen was a guard at the Waldlager forest camp in Bobruisk, Belarus, where Jews too sick, fatigued or malnourished to work were forced to dig their own grave, strip naked and shot in the back of the head.

After the war, Rasmussen, changed his surname to hide his dark past and slipped into mundane suburban life where he got married, had two children and became a film company lighting technician.

Now 90, Rasmussen, a widower, potters around the affluent enclave in Copenhagen and idles away his time laughing and joking with his friends at a walking club for the elderly where no-one knows of his history.

He could be the next former fascist to be tried over his involvement in the mass murder of Jews.

Nazi hunters at the Simon Wiesenthal Center have held talks with prosecutors in Denmark to make the case for Rasbøl to be prosecuted over his role at the Waldlager death camp.

A Waffen SS volunteer, one of 6,000 Danes to sign up during the Second World War, Rasmussen admitted he was at Waldlager - but insisted he was there to train to fight on the front line and took no part in the killings.

The camp was created in 1942 after the Nazis invaded Brobruisk, which was home to 30,000 Jews.

Some managed to escape, but an estimated 20,000 Bobruisk Jews were killed in the months following the German invasion. The rest were taken to the Waldlager labour camp.

Because of their occupation of territories in the USSR, the Nazis needed to establish a central supply base for the Waffen SS in central and southern Russia.

To do that they built a base in the forest camp close to the village of KIssyelevichi – five miles from Bobruisk.

It's one of the less well known Nazi 'labour' camps, but in an interview with the Danish police on June 6, 1945 Rasmussen - part of the Free Corps Denmark - told of the horrors of what went on there.  

He revealed how prisoners who were no longer fit to work were ordered to dig their own graves in the forest at the edge of the camp and were shot in the head.

'In 1942 to 1943 the imprisoned Rasmussen had guard duty at the Waldlager military camp,' read the police report from the time.

'During this duty he witnessed the execution of several Jews by shots to the back of the head. 

'The Jews were used to dig ditches, keep the roads clear of snow and perform regular cleaning duties at the military camp. 

'The temperatures were sometimes down to minus 25 to 30 degrees, and the Jews were poorly clad and very poorly fed. 

'People were sick every day in the prisoner section of the camp. And when they were no longer fit to work, they were ordered out to big mass graves placed at the edge of the camp grounds. Here they were ordered to strip naked and lie down on their bellies in the holes. 

'When they had done that, they were executed with a single shot to the back of the head, after which the corpses were covered with dirt and snow.' 

Of the 1,500 Jews who were taken to Waldlager from the ghetto in Warsaw in 1942 – only 90 survived when it closed the following year.

And only three survivors have ever spoken of what happened to them there. 

Yizhak Wasserstein, from Warsaw, the camp's cook, told of the brutality and said he was convinced he only survived because of his job as the chef.

One of the few witnesses who have told what took place there was Dutch SS-guard Lambertus Loyen.

Wracked with guilt, Loyen voluntarily confessed to crimes committed at the camp and said he hadn't slept a night since he left. He was sentenced to life in prison in a Dutch court in 1976 and committed suicide in his prison cell.

His testimony included some of the most brutal and horrific stories to come out of any World War II death camp.

The mass graves were so frequently used that the soldiers didn't bother to cover the corpses with dirt between rounds, he said, telling also of sexual death-violence and drowning of prisoners for entertainment.

Prisoners were also buried in the ground with only their heads sticking out, after which fellow prisoners were forced to kick them to death. 

Rasmussen's case has only come to light after Danish authors Therkel Straede and Dennis Larson investigated his past - interviewed him twice in 2009 and 2010 - and wrote 'A Book of Violence' on their findings.

Straede, history professor at University of Southern Denmark, told MailOnline: 'He took part in the guarding of the camp, both the inner perimeter and the outer. That made him part of the extermination-machine. 

'I can't tell whether he can be sentenced according to Danish law, but if he was German he definitely could. Oskar Gröning was prosecuted and sentenced for basically the same thing,' he said.

Straede said the the Free Corp Denmark members were methodically submitted to crimes against humanity as part of their training.

'They were basically being trained for extermination, before being sent to the eastern front. It was a conscious strategy to introduce the recruits to these types of crimes from day one,' he said.

In 1948 Rasmussen was jailed for six years in Denmark for shooting and injuring a young Danish man. His sentence also took into consideration the charge of treason against Denmark during WW2.

In 1944, while on leave, he and another Danish SS soldier had taken a girl to the cinema in Copenhagen when another man started to 'bother them'.

In the confrontation, the two SS-men started shooting at the crowd that had gathered around them. 

Rasmussen and his comrade got away with the help of Wehrmacht soldiers, who came to their rescue. 

After the imprisonment, Rasmussen changed his surname to Helmuth Rasbøl and quietly got on with his life.

He got a job as a technician trainee at the Nordisk Film studios and spent most of his working life as a lighting technician on film and TV productions.

He married and had two children and has lived quietly in the Gladsaxe borough north of Copenhagen.

His wife died 2001 and Rasmussen can often be seen watching the world go by at the Frederikberg Gardens in Copenhagen or out with his friends at a walking club for the elderly. 

'That he served as a guard at the camp any number of times is beyond doubt. That, according to German law, made him part of the killing machine,' Mr Straede said.

Speaking to MailOnline Mr Straede accused the Danish authorities of failing to fully investigate Rasbøl and the 6,000 Danish Nazi volunteers for their roles in the Second World War.

'It's extremely frustrating that the Danish state prosecutor and the government didn't react at all to the findings of our book. It's a scandal that Denmark hasn't taken the initiative itself to launch an investigation,' he said. 

Danish police said today the complaint has been passed on to a newly formed special unit tasked specifically with the investigation of international war crimes and genocide.

'All I can say for the time being is that we have received the complaint and have started investigating the allegations,' said Arne Bjørn Hansen, Detective Superintendent at the war criminals hunter unit. 

WHY 6,000 DANISH SOLDIERS VOLUNTEERED TO JOIN THE NAZIS IN WW2

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