This article reproduces documents related to an aborted SCAP war crime investigation into the Ukishima-maru incident conducted during the Allied occupation of Japan. The incident involved the sinking of a repatriation vessel (the Ukishima-maru) on 24 August 1945 after it apparently struck a mine in Maizuru Bay, causing hundreds if not thousands of deaths among the Korean forced laborers aboard the vessel. The documents include the testimonies of Korean survivors (submitted in Japanese and translated into English by SCAP officers) which supported the claim that the incident was planned by the Japanese authorities. Though the investigation was eventually terminated by SCAP which dismissed the testimonies as “hearsay account[s]”, the documents are a useful window into the tense situation faced by Koreans in Japan during the immediate postwar years and cast light on the nature and quality of SCAP efforts to pursue justice in its investigation.