The owner of the one of the vessels which came to the aid of the boat stricken by fire near Lyttelton, says it could become an environmental hazard.
The blaze broke out on the Amaltal Columbia around 5.30 this morning.
The 43 crew battled the blaze until most were ordered to abandon ship.
The San Discovery arrived second at the scene and is heading back to Lyttelton Port with 12 crew onboard.
Sanford managing director Eric Barrett, who owns San Discovery says oil and fuel leaks are a possibility.
"If the vessel's structural integrity is still ok, then there's no danger of any leaks or oil leaks, but if in fact the structural integrity starts to be compromised, that's a possible outcome."
The crew of the Amaltal Columbia managed to transfer safely to two other ships sent to the area after their mayday call.
The Talley's fishing boat is still ablaze but it looks like the fire is under control.
Chief Executive of the fishing division of Talleys, Tony Hazlett says he's just flown over the scene.
"It's sitting at about a 5 degree lisp, but to me it looks very salvageable. We are hoping to get a line onto that boat by about 4 o'clock this afternoon and have it under tow, whether we bring it back into Lyttelton or not, I'm not sure, we've got to wait for authorities to give us the clearance to do that."
Mr Hazlett says all the crew are safe and well but they will be checked over when they make it to land.
The Fire Service says the crew onboard the Talley's fishing vessel that was on fire is now all safely off.
Lyttelton Fire Chief Mark Buckley says everyone is now off the vessel with company representatives on their way to the scene.
"There are Talleys reps going out to have a look to see what the situation is. We've been stood down. We basically started to gear up to go out but we got stood down because everybody's been evacuated off the ship."
A Ukraine-flagged fishing vessel has come to the rescue.
Maritime New Zealand spokesman Steve Rendle says that includes the ship's captain and chief engineer.
"We'll make sure that the crew are safe and get them back to dry land, so that's the priority."
Mr Rendle says the decision to abandon ship was made when the fire cut the vessel's main engine.
The fire broke out in the ship's meal hold.
It's been sealed off in an attempt to starve the fire of oxygen.
Newstalk ZB understands the abandon ship order was given after the seals of the hold's doors melted from the heat of the fire.
Another fishing boat has rendezvoused with the vessel and will rescue the crew from the life rafts.
Maritime New Zealand says the 64m Amaltal Columbia is 45 nautical miles, or 85km, northeast of Lyttelton Heads.
An urgency call was put out by the boat just before 5.30am, that was quickly elevated to a mayday call.
An RNZAF Orion is in position above the vessel monitoring the situation.
There is a three metre swell in the area with winds of 15–25 knots.
Photo: Lyttelton Port (NZ Herald)