In 1981, professor of Modern Jewish History and Holocaust expert Deborah Lipstadt wrote in a letter to the Los Angeles Times that "the fact is, the Nazis never used the bodies of Jews, or for that matter, anyone else, for the production of soap.
The soap rumor was prevalent both during and after the war. It may have had its origin in the cadaver factory atrocity story that came out of World War I. The soap rumor was thoroughly investigated after the war and proved to be untrue."