Police from the canton of Appenzell Innerrhoden responded to information that the man had not been seen for some time, and went to search the woods. There they found the man's body in illegally-built premises that were virtually invisible from the air.
They also discovered a large number of explosives.
The hut has a kind of living room and bedroom, and was powered by a diesel generator and wind turbine. A large number of barrels stored heating oil for the tank.
Further information also led police to a workshop kept by Manser where they found and confiscated a number of weapons.
The body was so decomposed that he must have been lying dead for some weeks, the Institute for Forensic Medicine in St. Gallen concluded. The police also confirmed that the man died from natural causes.
"Sepp was not a strange hermit. He was a dear man, certainly not dangerous," Esther Inauen, a 53-year-old waitress at the Schäfli restaurant in Steinegg, told news site Blick.
Manser had started building the hut in about 1962 on his brother’s land. After working gradually on the construction for years, he finally move there in October 1977.
“I don’t know why he moved to the woods,” Manser’s brother, Franz, told Blick.
“I wanted no part of it.”
One of ten children, Sepp Manser had never received any formal training. He started life as a farm-hand and then worked in a gravel pit. He was married for a short time only, his brother told the website.
The explosives have already been disposed of by the environmental agency.