Vienna's specialized armed police unit WEGA arrived around 10 pm in the Messie apartment building in Aichholzgasse, to find the badly decomposed body of an as-yet unidentified victim, with the axe still embedded in the corpse, and covered with a blanket.

The apartment was totally trashed, according to police, but was still home to the suspect, who is thought to have lived with the body in the living room for around three and a half months.

The suspect surrendered himself peacefully in the bedroom.

While police don't have confirmation of the corpse's identity, they suspect that a 50-year-old migrant worker from Poland who was sharing the apartment became the victim after some kind of dispute.

Police spokesman Paul Eidenberger said that the 52-year-old suspect had been staying with a friend, and had complained he couldn't sleep at his own apartment because of the body in the living room.  The friend told another friend, who was so disturbed that he contacted the police station in Ottakring.

According to the acquaintance, the German suspect was suffering from a severe mental illness.  He has already confessed to the murder in custody, however the background of the killing and the identity of the victim have not been disclosed.

The Vienna prosecutor's office has ordered an autopsy.