Authorities in China have halted imports of all milk products from New Zealand and Australia after Fonterra said that it has contaminated products to the country.

Fonterra, which is the world's biggest dairy exporter, admitted this weekend that products exported to China, Malaysia, Vietnam, Thailand and Saudi Arabia included contaminated New Zealand-made whey protein concentrate. The cooperative also said that the contaminated protein concentrate were added to products including infant milk powder and sports drinks.

New Zealand Trade Minister Tim Groser said that Chinese authorities have halted import of milk products from the two countries after the revelation from the company. Prime Minister John Keyraised questions over why the cooperative took so long to inform the public about the contamination when the products were made in May 2012.

“When, your whole business is about food safety and food quality, you think they'd take such a precautionary view to these things and say if it's testing for some reason in an odd way that (the product) would just be discarded till they're absolutely sure it's right,” Key said.

About a fourth of New Zealand's exports are made up of Dairy produce and the industry has an impact on the currency valuation. The New Zealand dollar fell to76.93 U. S. cents today, which is its lowest level since 8 July, 2013. The Fonterra Shareholders’ Fund fell as much as 8.7 per cent that led to a 0.4 per cent fall in NZX50 Index.