Fonterra says it will cut prices for its Anmum brand milk products in China after the government started a probe into possible price-fixing.
The products include specially formulated milks for women planning to start a family, during pregnancy and while breastfeeding, as well as products for infants and young children.
The farmer co-operative will reduce prices by 9% next month, the sixth foreign company to cut prices since the probe began.
Fonterra says the move is meant to ensure its products remain competitive.
The Chinese government said it had proof foreign companies were selling products at high prices.
It said prices had increased about 30% since 2008, the same year melamine-tainted baby formula killed six infants.