The man who threatened to spike milk formula with 1080 was behind a rival pest control product and struggling for cash, the Crown says.
The 60-year-old who pleaded guilty to two counts of blackmail over the fiasco can now be revealed as Jeremy Hamish Kerr of Mellons Bay, East Auckland.
He has been convicted over the threats, which saw infant milk formula pulled from supermarket shelves, but disputes some of the Crown's allegations.
Those issues will be explored before Justice Geoffrey Venning in the High Court at Auckland over the next two days.
Crown prosecutor Christine Gordon, QC, explained that Kerr earned royalties from a product called Feratox - a cyanide-based alternative to 1080.
But she said sales of the product were on the decline and the income was not enough to live on.
At the time the threats were sent, Kerr's credit card was almost maxed out and he could not make the minimum repayments, Ms Gordon said.
In a police interview, he downplayed the issues saying it was not "anything extreme".
In a witness statement, former colleague Paul Aylett told the court a 1080 ban would see a rise in the use of Feratox by as much as 30%.
And another witness Graham Wright spoke about Kerr's preoccupation with money.
"He was always dreaming about boats and holidays and always talked about spending money ... Money was in the background of everything he did," he said.
"I'd describe his spending as extravagant. He would buy the biggest and best machinery; much more than we needed."
An ANZ staffer also told the court about Kerr increasing an overdraft facility on his mother Judith's account from $10,000 to $50,000, which he was permitted to do since he had enduring power of attorney over her estate.
When the bank contacted Mrs Kerr she "knew nothing" but they approved the application after the defendant provided them with documentation about his authority.
The Crown says Kerr typed the blackmail letters and produced address labels himself, as well as mixing the infant formula with the 1080 and splitting it between the two envelopes while wearing gloves.
He allegedly drove to Marton one night and posted the two packages from Paraparaumu.
A criminal investigation started when they were received by Fonterra and Federated Farmers in November 2014 threatening to poison infant formula if New Zealand did not stop using 1080 by the end of March.
The public was told of the threat in March and formula was taken off supermarket shelves and held securely to prevent contamination.
In what became known as Operation Concord, 60 people were considered of significant interest and approached to be interviewed by police.
More than 2600 people were considered over the course of the investigation, which cost police $3 million, Police Commissioner Mike Bush revealed when the man was arrested in October.
Police said they believed the arrested man acted alone and no one else has been charged.
Blackmail is punishable by up to 14 years in jail.
Kerr's police interview will be played to the court this afternoon.
