Skellefteå, on Saturday a man in his 55s was found deceased in a residence.
Initially, there was no suspicion of a crime. Relatives were informed.
Thereafter, information arrived that the man had been subjected to assault earlier in the week.
The police are investigating the information about the assault and whether there is any connection to the man's death.
A suspected man was apprehended on Sunday. He is lawfully suspected of assault and causing another person's death.
The case is led by a prosecutor.