Police have identified the body of a man found in the Waikato River on Sunday but an autopsy has not revealed how he died.
The death of Hamilton man, Kimiora Te Hau, 45, remains a mystery.
Detective Senior Sergeant Ross Patterson said police were still investigating the cause of death.
"Yesterday's examination has raised several lines of enquiry for police and at this point in time his death is still being treated as unexplained and will remain so until such time as we have information that confirms otherwise."
Mr Te Hau's body was recovered from the river south of the Horotiu Bridge.
He was reported missing to police the previous Friday but had been missing since early Thursday.
Mr Patterson said investigators would still like to hear from anyone who recalled seeing a man in a dark coloured hooded sweatshirt, dark pants, white sneakers with a red and black back pack near any bridges or by the Waikato River on the night of March 19.