Laughing at Auschwitz - SS auxiliaries poses at a resort for Auschwitz personnel, 1942

These photos were taken between May and December 1944, and they show Auschwitz officers and guards relaxing and enjoying themselves – as countless people were being murdered and cremated at a nearby death camp was. In some pictures, SS officers can be seen singing.

In others, they are hunting and in another, a man can be seen decorating the Christmas tree in what can only be described as a holiday in hell. The album also contains eight photographs of Josef Mengele - some of the very few extant snapshots taken by the infamous concentration camp doctor during his time there.

The images are important because there are few photographs available today of the "social life" of the SS officers responsible for the mass murder at Auschwitz.

These are the first free-time photographs to be discovered of SS officers from a concentration camp, although similar images exist for other camps, including Sachsenhausen, Dachau and Buchenwald.

The album was by Karl Hucker, assistant to the last camp commandant at Auschwitz, Richard Baer. Hawker took the photographs as a personal keepsake. Before his liberation by the Allies, Hawker fled to Auschwitz.

After the war, he worked in a bank, without recognition, for years. But in 1963 he was forced to answer charges in a trial in Frankfurt over his role in Auschwitz.

In his closing words at the lawsuit, Hawker claimed: "I had no chance of influencing the events in any way and I neither wanted them to happen nor participated in them. I did not harm anyone. and no one died in Auschwitz because of me."

In the end, however, he was convicted of aiding and abetting the murders of 1,000 Jews and sentenced to seven years in prison. He was released after serving five years. He died in 2000, at the age of 88.

The photographs were made public by the United States National Holocaust Museum in Washington. The museum obtained photographs from a retired US Army intelligence officer who came across the album in an apartment in Frankfurt and has now given them to the museum.

"These unique photographs clearly depict the contented world she enjoyed while looking after a world of unimaginable misery," museum director Sarah Bloomfield said in a statement.

"They provide an important perspective on the psychology of narcissists". The director of the museum's photographic reference collection, Judith Cohen, said that there are no photographs that depicted anything disgusting, "and that's exactly what makes them so terrifying".

Some published photos from Karl Hucker's album "Laughing at Auschwitz" are collected in this photo album.