Visitors to Auckland Zoo's kiwi enclosure the "Night Forest" were evacuated today after staff smelled smoke through the building.
Three fire appliances and the hazardous materials unit attended after the chemical smell was noticed.
No fire was found and fire officers later discovered there was a leak in a refrigeration unit.
Jooles Clements from Auckland Zoo said visitors were evacuated immediately.
"As soon as staff noticed the smell they have evacuated the building and followed the safety process," he said.
"The fire service have discovered the smell was coming from a refrigeration unit in the Night Forest but have said it is inert and there is no danger to people or animals."
Fire Service northern communications shift manager Jaron Phillips said the fire service were called at 1.42pm after the smell was noticed.
The zoo is part of a valuable kiwi rehabilitation programme that has seen 300 eggs taken from the wild, hatched in captivity and reintroduced to their natural habitat.
There are currently two pair of brown kiwi housed in the enclosure.