New Zealand supplied Agent Orange chemicals to the US military during the Vietnam war, a government minister has revealed.
The disclosure led to immediate claims that New Zealand was in breach of the Geneva convention and could face a flood of lawsuits from veterans and Vietnamese.
Transport Minister Harry Duynhoven said the highly toxic chemical was sent to a US base in the Philippines during the 1960s.
"The information that has been given to me is that products used to make Agent Orange were shipped from New Plymouth to Subic Bay in the Philippines," he told the Sunday News newspaper.
After nearly three decades of official denials, a high-level parliamentary committee formally acknowledged late last year that New Zealand soldiers in the Vietnam War were significantly exposed to Agent Orange, but no mention was ever made that the country was a supplier.
Although the National Party was in power during the Vietnam War, Duynhoven said his current Labor government was responsible for setting the record straight.
"Any government has to deal with the situation it finds itself in and it's always a problem if previous governments leave a mess."
Veterans spokesman John Moller said the government must compensate ex-soldiers and their families, some of whom have suffered generations of health problems.
"It's bloody unacceptable what the New Zealand government has done to us and the other countries involved in the war," he said.
"Through their deceit, cover-up and negligence, the New Zealand government has the blood of thousands of Kiwis, Vietnamese, Australians and Americans on their hands."
Under the Geneva Convention, countries cannot be party to chemical warfare and must declare the use or supply of defoliants during conflicts.
The vice-chancellor of Canterbury University, Scott Davidson, an authority on international law, said the government had left itself open to lawsuits from Vietnamese. US lawyer Constantine Kokkoris, who represents Vietnamese victims of Agent Orange, said he may sue the New Zealand government.
"It is my intention at this time to look into the possibility of bringing a class against against the New Zealand government," he said
Davidson said if negotiations between Kokkoris and the government broke down, the UN could be called on to find a setting for a court case.
From 1961 to 1971, the US and South Vietnamese military sprayed millions of liters of toxic herbicides, mainly Agent Orange, over South Vietnam to destroy the vegetation used by communist forces for cover and food.
Hanoi says the defoliant has caused health problems for more than one million Vietnamese and continues to have devastating consequences. A study released last year found that Agent Orange was still contaminating people through their food. Dioxin, the defoliant's deadly component, can cause an increased risk of cancers, immunodeficiencies, reproductive and developmental changes, nervous system and other health problems.