Heavily-redacted documents detailing the New Zealand Government response to the 1080 infant formula threat were published earlier today by the New Zealand Ministry for Primary Industries (MPI) following a series of Official Information Act (OIA) requests.
Blackmail letters containing a threat to contaminate infant formula with 1080 unless New Zealand ended its use of the pest control poison by the end of March were received by Fonterra and Federated Farmers in November 2014.
Biodegradable 1080, the salt form of a toxin found in several plants, is applied aerially in New Zealand to kill pests such as possums, an animal blamed for the spread of bovine tuberculosis.
Samples of milk powder sent with the letters tested positive for 1080.
At the time, the Officials Committee for Domestic and External Security Coordination (ODESC) - a New Zealand Government committee - said it "considered it undesirable for detail of the threat to be made public."
“Officials strongly recommend that this matter be closely contained and not discussed with anyone else unless they have specific need to know," a note sent to Minister following an ODESC meeting reads.
This, another document added, was in line with the deadline set in the letters sent to Fonterra and Federated Farmers.
"The letter states that the notice is private and confidential and will remain as such unless the requirement to stop using 1080 is not met," it said.
"If detail of the threat is made public then full transparency is the best method of maintaining consumer confidence and relationships with our trading partners - subject to undermining the police investigation," it added.
New Zealand Police announced it was investigating the threat on March 10.
Just over a week later, on March 18, New Zealand Police announced that several tins of infant formula were being tested for 1080 following calls about packaging damage.
All the infant formula tested came back negative, it said the next day.