An original letter and an Easter card written by one of the SS officers who guarded the Nazi concentration camp Auschwitz, was presented at the camp this week with experts hoping it can help show the daily life of officers during the Second World War.
The letter, sent to the museum by an anonymous donor, dates from April 1, 1944 and includes a postcard depicting German tanks.
On the reverse the author, Stefan Dilmet, wishes his friend Ludwig Fitterling a Merry Easter.
Memories of survivors, witnesses and victims of the Holocaust are shown in museums and camps all around Europe, but it is rare to find memories, letters and private photographs of soldiers who worked at the camps.
After World War Two many tried to hide their shame and whitewash themselves by eliminating every trace
, and most never admitted their guilt.
The Auschwitz Memorial made an appeal in January to Germans and Austrians to donate to researchers any documents they may have from the Nazi era.
Nazi German occupation forces set up the Auschwitz-Birkenau camp in Oswiecim, around 70 km (45 miles) from Poland's second city, Krakow.
Between 1940 and 1945, Auschwitz developed into a vast complex of barracks, workshops, gas chambers and crematoria.
More than a million people, mainly European Jews, were gassed, shot or hanged at the camp, or died of neglect, starvation or disease, before the Soviet Red Army entered its gates in early 1945 during its decisive advance on Berlin.