A Maritime New Zealand (MNZ) official is today expected to visit a Korean fishing boat after a Ministry for Primary Industries (MPI) fisheries observer lost part of an arm on the ship.
The man was winched off the boat just before darkness closed in on Friday about 105 kilometres southeast of Bluff.
The man has been identified as Martin Bowers. His left arm was torn out of its socket and part of the arm was mutilated, according to reports.
An MNZ spokesman said the ship, the Sur Este 700, had since docked in Timaru and would be visited today.
He was unsure when the injured man would be interviewed.
It was a race against the gathering dark for the Otago Regional Rescue Helicopter, which made the hour-long flight from an airfield near Mosgiel, so the injured man could be winched aboard while it was still light.
"It would have been a major issue had we not got there before dark," rescue helicopter chief pilot Graeme Gale said.
An intensive-care paramedic was put on board the boat first to move the patient to the bow of the ship, from where he could be winched off.
The operation at the ship, to the point where the injured man was on board the helicopter, took about 30 minutes, and part of the return trip was made in darkness.
MPI said the man had undergone surgery at Dunedin Hospital.
Director general Martyn Dunne had been in touch with the injured staff member and his family, who were with him.
"As director general I am deeply concerned by what has happened," Dunne said.
"Our thoughts are with our staff member and his family. There will be an investigation into this incident, but right now our focus is on supporting him and his family.
"MPI's fisheries observers do critical work, often in difficult conditions, to assure the sustainability of New Zealand's fisheries."
Last April the 58-metre long Sur Este 700 struck rocks while sheltering off Stewart Island and ruptured a fuel tank.
Diesel from the vessel's 23,000-litre tank spilled into the ocean, but the crew was able to transfer about 20,000 litres of fuel to another tank on board.
After the incident, the boat went to Timaru under its own power.