Kennelly said police are still looking for three missing crewman who absconded off the vessel overnight.
"This incident occurred in the Southern Ocean, within international waters, but New Zealand is the closest country so we have the obligation to investigate", Kennelly said.
"Police have an obligation to the coroner to investigate all deaths that occur within the coroner's jurisdiction."
Kennelly said it wasn't a criminal investigation.
"This has been reported to police. We are working with the local port authority to locate the individuals, who are believed to still be within the port," he said.
Fairfax reported five people were swept overboard while chipping ice off a funnel in the Southern Ocean.