Himmler at the brothel in Mauthausen concentration camp Barrack 1 in October 1941
Set just behind the notorious Work Makes You Free gate at Auschwitz concentration camp lies one of the lesser-known horrors of WWII - a brothel for prisoners.
In a diabolical scheme aimed at encouraging inmates to work harder, 76 years ago this month Gestapo monster Heinrich Himmler ordered brothels to be set up in concentration camps across Nazi-occupied Europe.
The twisted plan conceived in October 1941, was aimed at increasing prisoners' productivity by offering the starved and tortured inmates a bonus system - if they worked hard enough they would be 'rewarded' with a visit to the camp brothel.
The first 'Dolls' House', as they were known, was set up a year later in 1942, behind barred windows at Mauthausen concentration camp in Austria.
This was followed by more in Ravensbruk, Buchenwald, Dachau and Flossenburg, among others. In total there were ten death camp brothels.
Two of the largest were in Auschwitz, in Nazi-occupied Poland, with the main brothel nicknamed 'Puff' sitting just behind the sinister Arbeit Macht Frei entrance in Block 24.
Established at the beginning of WWII following Hitler's invasion of Poland, Auschwitz grew to become the largest killing machine in history.
An estimated 1.1 million people were murdered through executions, beatings, slave labour and gas chambers.
The man charged with implementing the plan was SS doctor Siegfried Schwela.
In a chilling meeting with prison doctors he laid out his blueprint for the running of the brothels, instructing staff to ensure both male and female prisoners were 'clean', the women were sterilised and only the missionary position could be used.
He also demanded that SS thugs watch through spy holes to make sure the women didn't spend more than 15 minutes with each prisoner.
And he imposed strict race laws, insisting that only German men could visit German women and Slavic men could only meet with Slavic women. Jews and Russian prisoners were forbidden.
Schwela was killed by the resistance before implementing his plans, but in August 1943 and November 1943 both brothels came into operation under the command of SS beast Oswald Kaduk.
Set just behind the notorious Work Makes You Free gate at Auschwitz concentration camp lies one of the lesser-known horrors of WWII - a brothel for prisoners. Pictured: Auschwitz entrance with brothel on the left just past the gate
This image shows female prisoners in Auschwitz who were deemed suitable for work but did not work in the brothel. Non-Jewish women were lured into volunteering with promises of better living conditions and better food rations
Non-Jewish women were lured into volunteering with promises of better living conditions and better food rations.
Mainly in their 20s, the women were made to have sex with an average of 6-8 men every night between 8 and 10pm. They also had to 'work' on Sunday afternoons.
As many as 21 women prisoners worked in the Auschwitz brothels which were known as Sonderbauten (special buildings). The final brothel was opened in 1945, the year the Second World War ended.
Emaciated prisoners chosen for the brothels were given a humiliating medical check and had disinfectant cream smeared over their genitals.
Their names were called out in public role calls and they were force-marched into the brothel.
But often the men were too physically weak or ill to engage in intercourse.
Iga Bunalska from the Auschwitz Study Group told MailOnline: 'SS men would come to the building as a new transport was being registered, tell them they are looking for women to do some light work.
'The women volunteered to do it. Some of them would change their minds when they learned what the work was about, but a lot of them stayed.
'If a woman was pretty and healthy - they were checked by the doctors before being accepted - they would start working in the brothel. Of course, the women could not be Jewish.
The first 'Dolls' House', as they were known, was set up a year later in 1942, behind barred windows at Mauthausen concentration camp in Austria. Pictured: Female prisoners, who did not work in the brothel, at roll call in Auschwitz
The twisted brothel plan conceived in October 1941, was aimed at increasing prisoners' productivity by offering the starved and tortured inmates a bonus system. Pictured: A brothel room in Buchenwald concentration camp
'The women were given a warm place to live, each of them had their own room with nice furniture.
'They were given additional food from the SS kitchen, luxurious clothes and underwear coming from the warehouses of the goods stolen from the people who were killed in the gas chambers.
'They were given all the medical care they might need. All of that made surviving the camp much easier.'
She added: 'The brothels were opened every day in the evening, after the main evening roll-call, when other prisoners were sometimes still coming back to the camp after a day of tough work - there was a huge contrast between the women, and the other prisoners.
'The women could see how the prisoners looked, how tired, how beaten up and bloodied they were.'
Haunting prisoner testimonies unearthed by the Auschwitz Study Group at the Auschwitz museum in Poland show the reaction of prisoners to the brothels and the women who worked in them.
One prisoner called Jozef Szajna recalled: 'The brothels were just part of how the SS tormented the prisoners.
SS doctor Siegfried Schwela who introduced the brothels to Auschwitz In October 1941
'Everybody who thinks that Block 24 was some kind of a gift given to prisoners doesn't know about Auschwitz at all.
'It was built to humiliate people. It was just another example of German cynicism and cruelty. The brothels were nothing unusual. They were just another crime of German national socialism.'
Another prisoner, Mieczyslaw Zając, said: 'Everybody was gathered on the roll-call square. The Lagerfuhrer was very proud when he was handing the very first coupons to the newly-opened brothel in Auschwitz.
'He was reading the numbers out loud and gave prisoners the coupons when the whole camp was watching. One of the prisoners rewarded this way was Professor Henryk Mianowski, as he was working very well - he was teaching chemistry.
'He had a huge problem with trying to explain to the Lagerfuhrer that he would prefer a piece of bread or some more soup.'
The Lagerfuhrer in question was the Deputy Commandment of Auschwitz, Hans Aumeier.
A particularly vicious Nazi who gained a reputation for brutality, he was sentenced to death in 1948 and hanged for war crimes.
Survivor Zofia Bator-Stepien recalled how one girl was driven to working in the brothel out of desperation for a slice of bread.
She said: 'When they announced they were looking for volunteers for very light labour, she volunteered. She didn't know the kind of work she was supposed to do.
'When the doctor finished checking her he asked her if she had any idea where she would be going. She said she didn't but that she'd been told it would be easy and she'd get a lot of bread.
'So he kept telling her: 'This work means you will have contact with men, and then I will perform a small operation on you to make sure you will never get pregnant.
Inside Block 24 today where the original doors with spy holes (left) are still used for offices of the Auschwitz museum staff
'Think carefully about it, even though it gives you a chance to survive Auschwitz, you are still young, you might want to be a mother in the future and it won't be possible.'
'She told him she didn't care about being a mother. She just wanted some bread.'
Further testimonies reveal the stark differences between the women working in the brothels and their fellow prisoners.
Prisoner Zofia Bator-Stepien went on to recall: 'I was watching a young girl. She had a beautiful hairdo, her eyebrows and eyelashes had dye on them, she was wearing a beautiful blue shirt with black lace, and she had a blue robe.
'She was wearing high-heeled shoes. She was walking very seductively through the block and the head of the block was leading her to the bed. She was so amazing for us. A woman wearing make-up in Auschwitz?
'The woman we were speaking to - after a couple of days of rest - she told us she could even work in the brothel up to nine months at least. She was very upset when they fired her, even though she was begging them not to.'
Block 24 in Auschwitz where the brothel known as Puff was located on the first floor. The camp leader demanded that SS thugs watch through spy holes to make sure the women didn't spend more than 15 minutes with each prisoner
Wilhelm Brasse, a photographer in the photo studio at Auschwitz said: 'When the women were brought to Block 24, the Political Department ordered me to take pictures of them.
'They came in laughing and relaxed. They were all very pretty. They were joking and giggling in front of the camera. Eight of them were Polish and seven of them were German.
'I was speaking to them and they were full of hope. They had hope, this work gave it to them.
'The Polish women were prettier. The German women were fat and blonde. The Polish were thin and attractive.'
It wasn't only the prisoners who had access to the women.
Although SS guards and officers were banned from sleeping with non-Germans, many took advantage of the brothel.
Iga Bunalska from the Auschwitz Study Group said: 'It was forbidden for the Germans to use it due to the racial laws implemented by the Third Reich.
'However, we know for a fact that there were soldiers stationed in Auschwitz using the brothels - German soldiers, but not only as there were a lot of people who came from different countries serving in the SS, Ukrainians, Belorussians and such.
Left: Block 24 in Auschwitz. Right: Part of testimony by prisoner Mieczyslaw Zajac talking about Puff brothel in Auschwitz
'It seems the regular soldiers were using the brothel quite often, as in many testimonies you can find information about the fact that the women in brothels got all the latest news regarding the front and the war situation.
'Of course, they were doing it illegally, probably by bribing Oswald Kaduk who was in charge of the brothel.'
After finishing their time in the brothels, some of the women were made camp functionaries and some survived the war.
But little is known about what happened to them and very few spoke of their experiences.
Ms Bunalska told MailOnline: 'Working in the brothel gave them a chance to live.
'I know we think about it now from a different perspective, but for a lot of them it came down to a very simple choice: it was either the brothel and survival or the gas chambers in Birkenau.'
The Auschwitz brothels were closed down in January 1945 when the camp was evacuated to escape the advancing Red Army.