Hamilton police want to reconstruct the movements of a man leading up to when his body was found in the Waikato River on Sunday morning.
He has been named as Anthony Chanpraseuth, 31, who lived in Hamilton and was of Thai descent.
An autopsy carried out yesterday confirmed he died from drowning.
The police want to hear from anyone who may have seen Mr Chanpraseuth in the city centre late on Saturday night or early Sunday morning.