Newshub can reveal pest control tool 1080 has allegedly contributed to the deaths of 27 farm animals since 2008.
Documents released under the Official Information Act from the Department of Conservation (DoC) show there have been four occasions where compensation has been made to farmers following the incidents.
Both the Department of Conservation and Minister for Conservation Eugenie Sage refused Newshub's request for an interview on the topic.
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National's Conservation spokesperson Sarah Dowie told Newshub the revelations are unfortunate, but her party still supports the use of 1080.
"This highlights the need for meaningful engagement when it comes to the use of toxins and 1080 on the conservation estate. National does support the use of 1080, we think currently it's the best tool in the conservation toolbox in the use of predator control as independently verified by the Commissioner for the Environment.
"However, no matter what regulations we have around the use of toxins, or no matter how many operational plans that DoC puts in place, accidents can still happen."
Belinda Cridge, a toxicology lecturer at Otago University, told Newshub it's not a surprise because 1080 is a poison that targets pathways all animals have.
"If they eat enough of it, if the bait is around and they get into it, then it's toxic to them. Some species are much more susceptible to the toxin than others. A lot of the time the management is about trying to make sure those species don't get it."
Dowie says a wide-ranging conservation toolbox is needed for pest control. She said there needs to be "frank conversation" about the use of biotechnology in the pest control space.
"Conservation Minister Eugenie Sage has been given official information and advice she should do that, she blatantly refuses. We certainly think New Zealand needs to have that conversation especially if we want to achieve Predator Free 2050."
Newshub previously revealed the Conservation Minister penned a letter of expectation to Predator Free 2050 Limited, explicitly telling the company not to invest in research into genetic engineering technology.
The Department of Conservation suggested it could be used to help rid New Zealand of predators.
"It's absolutely critical. We've had leading scientists in this country come out and say that without the use of biotech we will not eradicate our pests and not achieve our predator-free goal," Dowie said.
Cridge says there needs to be ambition to find new ways to fight pests.
"We've got a lot of tools which have a lot of different uses, but nothing's perfect. I think we need to keep driving forward and 1080 is one of those poisions we can use. It one of the most contentious we use but it's used for very specific areas and reasons."
When asked about the use of biotechnology, she says every tool that could be used for pest control needs to be looked at.
"As scientists we have an obligation to put as many options out there. It's then up to society to say what is acceptable, what do we want, how do we want to manage it. That's not a science call. That's very much about everyone in society having that discussion about how we use the tools that we've got."
Newshub revealed DoC has significantly increased its spending on finding alternatives to 1080. Since 2011, the trend in spending has jumped from $1.06 million a year to $3.55 million planned spend in 2018/19.
Documents that were also obtained by Newshub revealed officials warned the Environment Minister last year New Zealand will fall behind the rest of the world in the genetic technology space.
Advice said there could be lost opportunities including economic developments, medical treatments and combating the likes of kauri dieback and myrtle rust. It was recommended a public discussion was initiated.
Minister David Parker revealed no work was being done in the area.
Conservation Minister Eugenie Sage released a statement once the story was first published.
"They are unfortunate incidents and the deaths of cattle is distressing for the farmers, however DOC informs me that the operations undertook all precautionary safety steps including notifying the famers of the operation and putting up adequate signage. I understand that the livestock in question wandered into the operational area through substandard gates or fences.
"Aerial operations using biodegradable 1080 are the safest and most effective means of knocking down rats, stoats and possums over large areas of rugged terrain," she said.