Private letters written by SS commander Heinrich Himmler will be made public for the first time when they are published in a German newspaper.

Die Welt is set to publish Himmler's private letters, notes and photographs detailing the rise and demise of the Nazi regime, from 1927 to five weeks before his suicide in 1945.

The letters show a more tender side to a man known as the architect of the Holocaust. They include courtship letters written to his future wife Marga, who ran a nursing home in Berlin, in 1927. The letters span the early months of their relationship, with Himmler signing them "Dein Heini" ("Your Heini").

The relationship started to break down in 1938 when Himmler began an affair with his private secretary, but he remained in touch with his wife and also wrote several times to his daughter, signing them "Euer Pappi" ("Your Daddy").

The letters are owned by an Israeli family and are held in a bank vault in Tel Aviv. Die Welt say the letters have been independently verified. Michael Hollmann, president of the German Federal Archive, told the newspaper: "We are sure about these documents. There is no reason to doubt the authenticity of the documents in Tel Aviv."

Michael Wildt, a German historian, said the letters were an important find for German war historians. "This is a dense body of private documents. There is nothing like it for any other member of the Nazi leadership."

Heinrich Himmler was a leading member of Hitler's Nazi Party during the Third Reich. Himmler was one of the most powerful men in Nazi Germany and was responsible for building extermination camps, and oversaw the running of concentration camps during the Holocaust.

Before the end of the war, Himmler offered to open peace talks with western Allies, leading to his dismissal from the SS and a warrant being issued for his arrest. Himmler attempted to go into hiding but was captured and arrested by British forces and committed suicide while under arrest on 23 May 1945.

The publication comes ahead of Holocaust Memorial Day in the UK, on 27 January. It commemorates the anniversary of the liberation of Auschwitz concentration camp by the Soviet Union in 1945.