Two people needed medical treatment after being exposed to ammonia from a fire-damaged fishing ship in Lyttelton.
Emergency services were alerted to an ammonia leak at Lyttelton Wharf at 12.05pm.
St John ambulance spokesman Ian Henderson told NZ Newswire two men were treated at the scene by paramedics.
A Fire Service spokesman confirmed the leak had come from the Amaltal Columbia fishing vessel, which caught fire off the Canterbury coast on Wednesday.
The spokesman said the Fire Service were dealing with the leak "as part of the ship process".
The 64-metre Talleys-owned ship, with 43 people on board, including two government observers, alerted the Rescue Coordination Centre to a fire in its hold about 5.20am on Wednesday.
The alert was upgraded to a mayday call at 6.20am and the crew abandoned ship about 8am.
The crew members were transferred to two vessels that had responded to the mayday call before returning to Lyttelton Port on Wednesday afternoon.
The ship was towed still burning into Lyttelton and docked about midnight, and fire crews continued battling the blaze until about 5am.
They had remained at the port on Thursday as a precaution.
The Transport Accident Investigation Commission (TAIC) has launched an inquiry into the fire, which could take up to a year to complete.
NZN