The incident happened around 10.30am in Frya, Sør-Fron, at one of Norway's largest pig farms.
The victim was a worker on the farm and police initially launched a search to find him after the explosion. At the time – just after the explosion – police had no confirmation as to the whereabouts of the man. The dead man's body was eventually recovered at 3.45pm.
According to Gudbrandsdølen, the barn was completely wrecked after the incident and the pigs were running around outside.
Locals helped staff and the farm owners gather the stray livestock. Injured animals were culled while the remaining animals were taken to another farm building to be looked after.
Sygard Forr Farm is one of the region's largest pig farms and there was around 400 to 500 pigs inside the barn at the time of the explosion.
Police chief Kai Førlandsås believes fertiliser in the barn's basement is the likely cause of the explosion, reported the newspaper Dølen.
Emergency services received a call at 10.40am on Monday morning telling of an accident at the farm. All emergency services, including an ambulance helicopter, were sent to the scene.