It was at ten o'clock on Monday morning that the rescue service, ambulance and police were alerted to the beach area around Stampen, where a dead man was found in the water.
During the day, the police were able to identify the person and confirm that it is the man in the 25-year-old who disappeared without a trace after a visit to a shopping center in Alingsås on 12 October.
When the man was reported missing, the police launched a preliminary investigation into illegal deprivation of liberty and kidnapping.
The heading is now changed to murder or manslaughter.
Relatives are notified.