He is the son of Hans-Juergen Höss, born 1937. He never knew his grandfather Rudolf, who was executed at Auschwitz in 1947, eighteen years before he was born. When he was 12 years old, he first learned about the history of his grandfather in school. His mother divorced his father in 1983, he himself is divorced and has three children. He states:
- Before he was hanged, my grandfather wrote to my grandmother that she should change her name. Both my grandmother and my father were in complete denial of his crimes, and so they adamantly refused to change their names. ‘Höss will remain Höss,’ my grandmother would say. I decided that if I kept the name, this would enable me to do my part in repenting in my grandfather’s name. It’s not so simple, of course – you always need to be careful about everything you say, because people are judging you. Sometimes people curse me on the Internet, and neo-Nazis are always trying to contact me. Ultimately, the name Höss is connected with Auschwitz, where millions of people were murdered.
After his parents divorced, Rainer started to search historic documents in German archives to find the real history of his grandfather. He worked together with the Institute of Contemporary History (IFZ). He received the rights to his grandfather’s archive, after research in Mauthausen and Buchenwald. He participated in the documentary Hitler's Children, and has made contact with victims and survivors of the Holocaust. From family archives and personal knowledge he testifies about the life his grandfather had in private and explains to youth, whom he visits in schools, how to see this in today's context.
During his life, he has made multiple visits to Auschwitz in person, the first time in 2009. During the visits, he talks with visitors and answers people's questions. He has stated that he would kill his own grandfather if he had the opportunity to meet him.
He wrote The Heritage of the Kommandant: On being part of a terrible family (German: Das Erbe des Kommandanten/Berlin: Belleville, 2013).
The Israeli journalist Eldad Beck considers Rainer Höss' involvement in Holocaust issues to be "motivated by pure opportunism." Beck, who interviewed Höss for the documentary Hitler's Children, has stated that Höss "continues trying to trade with his family's belongings dating back to the Holocaust."
- L'Héritage du commandant : le petit-fils du commandant d'Auschwitz raconte, Paris, Notes de Nuit éditions, 2016.
- The Nazi's grandson