New Zealand milk is safe and reports to the contrary are spreading misinformation, Prime Minister John Key says.
A finding in September said traces of Dicyandiamide (DCD) had appeared in milk tested by Fonterra.
DCD is used to inhibit nitrate leaching into waterways from fertiliser treatments and to reduce greenhouse gas emissions. Recent media reports in the Untied States and China have questioned the safety of New Zealand milk.
Key told Newstalk ZB he would be concerned if international consumers reacted to ''misinformation''.
''The situation here is that there is no health risk, at all."
''What's happened is the fertiliser has been put on farms. It gets put on twice a year, DCD, [and] that has shown very slight traces coming from one milk processing plant of Fonterra's,'' he told Newstalk ZB.
A person would have to drink the equivalent of a swimming pool-full of milk to be affected, Key said.
''Once you get these sort of stories written, even if they're incorrect, it's a big job to close them down.''
Fonterra chief executive Theo Spierings said the reaction to the findings were ''way out of proportion''.
''We have strong science and we are providing assurances about the safety of our products,'' Spierings said.
''Our testing has found only minute traces of DCD in samples of some of our products.
''It is important to remember that the minute traces detected were around 100 times lower than acceptable levels under European food safety limits.''
Fonterra said on Friday it supported moves by New Zealand's two main fertiliser suppliers to voluntarily suspend sales and use of DCD treatment on farm land until further notice.