A snake has been found on a South Auckland construction site where contractors were flushing out a new pipe.
The Ministry for Primary Industries (MPI) said the snake was dead and there was "no evidence of any further snakes and there is no threat to the public".
Contractors had been flushing out a new pipe at a construction site in Papakura before laying it, which is when the snake came out.
Biosecurity NZ aquatic and environmental health manager Michael Taylor said the agency, which is part of MPI, responded quickly to the snake discovery.
"One of our incursion investigators has picked up the dead snake. We haven't yet determined the species of the snake," he said.
"There is no evidence of any further snakes and there is no threat to the public. We will investigate how it arrived in New Zealand.
"We commend the actions of the worker for quickly alerting Biosecurity NZ of the detection in Papakura.
"Alerts from the public are an important part of the biosecurity system. They allow us to act quickly to eliminate biosecurity threats. We ask anyone who spots what could be an unwanted pest or disease to report the sighting to our emergency hotline on 0800 80 99 66.
"We intercept one or two snakes a year. They are normally not venomous and mostly arrive dead, due to treatment of imported cargo.
"Most snake species would be unable to survive New Zealand's relatively cool climate, especially the winter. However, a snake from a cooler area would have a chance of survival. If such a snake were carrying eggs, there is very small chance that the offspring could survive, but our advice is this is very unlikely.
"Biosecurity NZ takes the threat of a snake population establishing in New Zealand very seriously. This is why we have a multi-layered biosecurity system that involves strict import requirements, checks at the border and surveillance. It is also why we have trained personnel to handle detections safely and effectively.
"Our biosecurity system has proven very effective to date in preventing a snake population from establishing in New Zealand."
A spokesperson for the Department of Conservation told Newshub that the snake was a kind of boa or python.