 The sunken submarine's identity has later been contested as several Soviet submarines of Shchuka class were lost at that time in the area but the most likely candidates are either "Shch-320" or perhaps even more likely "Shch-308" as some Russian sources claim that "Shch-320" had been sunk by a mine earlier that month and that the initial unsuccessful attack by "Iku-Turso" had been against "Shch-307".On 30 July 1944 "Iku-Turso" attempted to attack a convoy targeting a tug but failed to reach firing position.On 24 August 1944 "Iku-Turso" ran into an obstacle — apparently an anti-submarine net - but was able to get loose.