The Hårsfjärden sabotage finding leaves the culprit unresolved

The court-martial judged sabotage the most likely cause of the Hårsfjärden disaster, although it identified no saboteur. Swedish escorts for German oil transports through Swedish waters supplied a possible Allied motive. British interest in such an operation is questioned here: the loss of Norway and Narvik had removed purchase as Britain's principal means of affecting Swedish ore supplies. The Soviet Union might have wanted to disrupt the traffic. An unexplained explosion that destroyed four German minesweepers near Helsinki three days earlier encouraged comparisons. Neither parallel timing nor possible motives settled the cause.