Police are searching for three crew members who ran away from their South Korean fishing vessel after it docked in Bluff overnight.
Their disappearance follows another crew member's death on-board and a second man receiving what's being described as "moderate injuries".
Police say the Chinese national died on November 20 while working on the vessel.
The vessel was fishing in international waters, but New Zealand police say they will investigate the death.
Meanwhile, police are trying to locate the missing fishermen, who are all believed to be from the Philippines.
Detective Sergeant Dave Kennelly says "we are working with the local port authority to locate the individuals, who are believed to still be within the port".
In 2011, Indonesian crew walked off the Korean-flagged Oyang 75 alleging abuse and underpayment.