The man allegedly behind threats to contaminate infant formula with the poison 1080 has had his case elevated to the High Court.

He faces two charges of blackmail but cannot be named for at least six months because of a suppression order.

Charging documents allege the action was financially motivated but court-imposed orders mean little else can be publicised.

The defendant appeared in the High Court at Auckland this morning where Crown prosecutor Natalie Walker said she and defence counsel had agreed the case should be moved from the district court jurisdiction.

Justice Graham Lang adjourned the matter until next month when the accused will be obliged to enter pleas to the charges.

A criminal investigation started when letters were sent to Fonterra and Federated Farmers in November last year threatening to poison infant formula if New Zealand did not stop using the pest-control poison by the end of March this year.

The public was told of the threat in March and formula was taken from 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 last month.

Police said they believed the arrested man acted alone and no one else has been charged.

According to court documents, the man "threatened expressly to endanger the safety of any person, namely infants, by releasing infant milk formula into the Chinese market contaminated with traces of 1080, with intent to cause Federated Farmers Incorporated to act in accordance with the will of [the man] to cause Federated Farmers to pressure the New Zealand Government to stop the use of 1080 in New Zealand".

Blackmail is punishable by up to 14 years' jail.