Hunt widens for "coward" behind New Zealand infant formula threat

Police and food safety officials asked for the public's help Tuesday in finding the person or people behind the threat to poison New Zealand infant formula.

Political and industry leaders from across the country united in condemning the threat in anonymous letters sent to farming and dairy industry leaders in November last year.

Prime Minister John Key said in a televised press conference that the government had planned to reveal the threat next week, but moved earlier after news media began asking questions.

He defended the delay in warning the public, saying food safety officials and the industry had to first ensure the entire supply chain was secure against any threat, while the police needed time to conduct a thorough investigation.

"We're advised it is extremely unlikely anyone could deliberately contaminate formula during the manufacturing process and there is no evidence that this has ever occurred," said Key.

"My message to New Zealanders, and parents in particular, today is that while it is very likely this threat is a hoax, we as the government have to take it seriously and I can assure you that we are."

The police had earlier urged the person or group responsible for the threat to come forward.

"The letter writer may not have really considered the implications of their actions when this communication was drafted. Now is the time to put this right by picking up the phone and calling us," Deputy Commissioner (National Operations) Mike Clement said in a statement.

The main opposition Labour Party said the threat was "an idiotic and extreme protest" that put the entire national economy at risk.

"Food safety and the health of children is the highest priority for all New Zealand's food producers and exporters," Labour Primary Industries and Food Safety Spokesperson Damien O'Connor said in a statement.

The opposition New Zealand First party said the threat was despicable and "terrorism of the worst kind."

"This not only risks over 14 billion NZ dollars (10.23 billion U.S. dollars) worth of dairy exports, but the livelihoods of hard working dairy farmers, their workers and their families," New Zealand First leader Winston Peters said in a statement.

Infant Nutrition Council Chief Executive Jan Carey said the threat was an "act of economic terrorism."

"We deplore the actions of someone who can only be called a coward and the threats he or she has made against Brand New Zealand and our industry, not to mention the anxiety this will cause to mothers who rely on infant formula," Carey said in a statement.

"This is likely to have serious ramifications, both domestically and in export markets."

Police said the letters sent to the Federated Farmers industry group and the Fonterra dairy cooperative were accompanied by small packages of milk powder that subsequently tested positive for the presence of a concentrated form of the poison 1080.

The letters threatened to contaminate infant and other formula with 1080 unless New Zealand stopped using 1080 for pest control by the end of March 2015.

Sodium monofluoroacetate, known as 1080, is a poison used to protect New Zealand's native flora and fauna against introduced pests such as possums and ferrets.

Its use has been controversial over the years with opponents saying it poisons native animals and contaminates the environment. Endi