The police's hottest clue before the investigation was closed in 1982 was that Sven Sjögren would have been murdered in a plot to take over the land his farm stood on.    

One theory is that Sven was shot and ground up into mink food in a large meat grinder on a mink farm.

Other testimonies indicate that the body was dumped in the sea or buried in one of Gotland's marshlands.  

See the documentary What happened to Sjögren?

on SVT Play, or at 21:00 on October 4 in SVT1.