The Investigation (1965) is a play by German playwright Peter Weiss that depicts the Frankfurt Auschwitz Trials of 1963–1965. It carries the subtitle "Oratorio in 11 Cantos". Weiss was an observer at the trials and developed the play partially from the reports of Bernd Naumann. The work premiered on October 19, 1965 on stages in fourteen West and East German cities and at the Royal Shakespeare Company in London. In 1966 the production was presented at the Royal Dramatic Theatre in Stockholm which featured sets and costumes designed by Weiss's wife, Gunilla Palmstierna-Weiss, and was directed by Ingmar Bergman.