A 65-year-old man has been detained, suspected of murdering the man.
Both men are from Germany.
The alarm was first raised on Thursday as a boat accident at sea in the Kattegat in Öckerö municipality, about 25 kilometers off the outer islands of the Gothenburg archipelago.
In a large rescue effort, the man was winched up from the sea. He was taken to hospital by ambulance helicopter, but his life could not be saved.
It later emerged that the incident is being investigated as a murder and that the men were on their way home from a sailing competition when they started arguing.
A trial against the suspect who was detained on Sunday can be expected at the earliest in November. The investigation is being conducted in collaboration with prosecutors and police in Germany, according to the prosecutor.
"We are now conducting supplementary interviews, carrying out technical investigations and awaiting the autopsy report," says prosecutor Maria Thorell in the press release.
