The death of the man, found on a boat in Nelson earlier today, is being treated as suspicious.
The unidentified man was found on a boat, moored in marshland along Queen Elizabeth II Drive in the South Island town, at 10:45 this morning.
Tasman Police are continuing the examination of the scene opposite the skate park and are expected to be there for the next couple of days.
In a statement detective inspector Paul Borrell confirmed the death was thought to be suspicious.
"Police have already had some positive leads from the public, but would still like to hear from anyone who may have information that could help the investigation."
He said given the drive was the main route in and out of Nelson there would have been lots of people driving past the scene.
"We would like to hear from anyone who may have seen anything suspicious in the area overnight or this morning."
Anyone with information should contact Nelson Police on 03 546 3895, or Crimestoppers, anonymously, on 0800 555 111.