In 1994, the personal letters of the Swedish fascist Per Engdahl were made public, posthumously revealing that Kamprad had joined Engdahl's pro-fascist New Swedish Movement (Nysvenska Rörelsen) in 1942, at age 16. Kamprad had raised funds and recruited members for the group, at least as late as September 1945. When he quit the group is unknown, but he remained a friend of Engdahl until the early 1950s.
Kamprad devoted two chapters to his time in Nysvenska Rörelsen in his book Leading by Design: The IKEA Story and, in a 1994 letter to IKEA employees, called his affiliation with the organization the "greatest mistake of my life". Kamprad explained his teenage engagement in New Swedish Movement as being politically influenced by his father and grandmother in Sudet-Germany. In 2011, journalist Elisabeth Åsbrink published a book Made in Sweden: How the Swedes Are Not Nearly So Egalitarian, Tolerant, Hospitable or Cozy As They Would Like to (Have You) Think in which she revealed that, by 1943, the Swedish Security Service had created a file on Kamprad entitled "Nazi", and that Kamprad had told her, during a 2010 interview, that "Per Engdahl is a great man, and I will maintain that as long as I live."