The snake found by workers at a South Auckland construction site is now being housed in a laboratory as part of a specimen collection.
Measuring just over a metre long, the carpet python from Australia is being kept at a lab in central Auckland after being examined by a snake expert yesterday.
Consultant herpetologist to the Ministry for Primary Industries, Dylan van Winkel, said the reptile most likely died when air pressure was used to flush out a pipe it was in on Tuesday.
"When I examined it yesterday, it was very freshly dead.
"Based on the condition of the animal, it was probably alive [just] before that," van Winkel said.
"It's a beautiful animal."
The carpet python, a juvenile male, is thought to have become trapped inside a sealed pipe from across the Tasman in the last few weeks.
Although non-venomous, carpet pythons kill their prey by wrapping their bodies around them - constricting them - until they suffocate.
He guessed it could have been in the pipe for up to a few weeks and could have survived without food for several weeks or months.
Contractors at the Papakura site raised the alarm with Biosecurity New Zealand and MPI officials when the snake popped out of the pipe during the flushing process.
Up to five reports of snakes found every year
Officials are still working to determine exactly how the snake slithered its way into the country.
The incident is one of about four to five reports of snakes being found - dead and alive - around the country each year, van Winkel said.
"Most of the incidents - about 80 per cent - that we're called to, the snakes are dead," he said.
But there was the odd time when they received a report of a live snake found inside a shipping container or an imported vehicle, for example.
"There was a recent incident in Te Ānau where a snake was inside a vehicle that had been imported.
"There are about 20 trained venomous snake handlers around the country and every two years we have a refresher course."
Van Winkel said in incidents where a snake was alive, equipment was used to capture it. They would never actually handle the reptile.
He said members of the public who had found themselves in that situation were quickly advised about what to do when they called MPI or Biosecurity NZ staff.
"If you can get a photograph, that could be really good - but of course we don't want you to get close to it.
"If it's in a vehicle, shut the vehicle and get away from it. And if it's in a shipping container, it's sealed straight away and a (snake handler) is sent out."
Van Winkel, who has been a herpetologist for 15 years, also works as a senior ecologist for Biosresearches.
He said the work they did was hugely important in this day and age, given many animals were becoming increasingly endangered.
"We have more reptiles in New Zealand than in Australia. It's very diverse.
"The work is partly conservation and about protecting wildlife. They need to be looked after too."