The fire alarm was received at 5:30 a.m. Monday after neighbors heard a bang, Borås Tidning writes.
A large number of units from the fire service responded to the fire, but it was quickly determined that the property could not be saved.
In the evening, the police announced that the incident was being investigated as suspected arson and that a technical examination had found what they suspect are human remains in the house.
Relatives of the person believed to be involved have been notified, and the cause of the fire is now under investigation.
"We don't suspect a natural fire unless someone lit it," Peter Apelqvist, duty investigator with the police, told Borås Tidning.
