The Food Safety Authority is backing an assertion by dairy cooperative Fonterra that any hormonal contamination in Chinese infant formula did not come from New Zealand milk.
Fonterra has confirmed that it supplies whole milk powder to Chinese company Synutra International, which is being investigated following accusations that premature breast development in some baby girls may be linked its formulas.
Synutra also buys milk from other sources.
Fonterra says there is a ban on the use of hormonal growth promotants in dairy cows in New Zealand.
The Food Safety Authority says that is backed by tight legislative and monitoring controls.
Assistant director Paul Dansted says the monitoring would show any unnatural hormone levels in New Zealand milk products.
Business analyst of Dave Mahon, of Mahon China Investment Management, says there is no damage to Fonterra in China and there is unlikely to be.
Mr Mahon, who is based in China, told Morning Report if there was an issue with a New Zealand product it would show up in more than just one company, as New Zealand supplies millions of tonnes of basic milk powder to China each year.