He was found after one of his neighbours contacted the police, reported public broadcaster SVT.
Police told SVT that his death was not believed to be suspicious, and that the man appeared to have been dead “for some time”.
A spokesperson said his relatives had been notified.
When police entered the apartment, the pile of post, letters and leaflet adverts reached the letterbox of the front door, wrote SVT. A local newspaper dated August 2019 was found in the pile, as well as an unopened letter from February the same year.
In 2019, a discussion about Sweden’s high number of single households, loneliness and the importance of looking out for your neighbours was sparked after a man was found dead in another Stockholm apartment after over three years.