Meanwhile, another man in his 50s, who was found seriously injured at the scene, has since been treated and discharged from hospital.
Police outside the Wikitoria Rd property where James butler's body was found. Photo / Wanganui Chronicle
Police launched a homicide investigation following the incident and last week the National Dive Squad was called in to search the Whanganui River while police carried out forensic examinations at the scene.
Police were hoping to find weapons the offenders involved in Butler's death may have discarded.
Last Wednesday police revealed the death of the 53-year-old Butler was not the result of a random attack and people in the incident were known to each other.