A group of friends searching for their companion found his body in a river in Stratford.
Detective Inspector Marc Hercock said Stratford police were notified of the discovery about 10.30pm on Tuesday.
The man is believed to be in his mid-30s and a post mortem is scheduled today.
"At this stage, the cause of death is unexplained," Mr Hercock said.
"It could be an accident, it could be anything, but we don't know yet.
"His friends said they hadn't seen him around in a couple of days, but that's not unusual."
He said it was unusual to find a body in the river but they were not treating the death as suspicious at this stage.
"But we always err on the side of caution and will look into all areas," Mr Hercock said.
Police are looking into the man's activities in the leadup to his death.
"We are in the process of interviewing witnesses and a scene examination is under way.
"One of our main priorities is formally identifying the man and informing his next of kin," Mr Hercock said.
Victim support services are being offered to the man's friends.
- © Fairfax NZ News
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