Countries across Asia are testing Chinese dairy products as fears spread over melamine-tainted milk - and some have banned these products outright.
Four Chinese children died after drinking contaminated milk and 13,000 others remain in hospital.
Four children in Hong Kong have now been diagnosed with kidney stones after drinking milk from the mainland.
State media say the company at the centre of the scare, Sanlu, failed to report the health problems for months. Sanlu is 43% owned by New Zealand dairy giant Fonterra.
According to a report by the state-run CCTV citing an official investigation, Sanlu began receiving complaints about sick children as early as last December but did not report the issue to the authorities until early September.
The report appears to be the first official admission that news of the health scare was deliberately suppressed.
Brunei, Indonesia, Singapore, Malaysia, Hong Kong, Taiwan, Japan, Bangladesh, Gabon, Burundi and the Philippines are all either testing Chinese diary products or pulling them from shops.
The BBC reports Starbucks has stopped serving drinks with milk in many Chinese outlets and many other large companies are testing products in some Asian locations or pulling them straight from the shelves.
Malaysia has expanded a ban on dairy products to include candies, chocolates and all other foods containing milk.
The problem was first revealed two weeks ago, when milk powder from the Sanlu Group was found to contain melamine, an industrial chemical.
At least 22 other companies have since become involved in the scandal. Milk products made by the Yili, Mengniu and other groups have been recalled from supermarket shelves in China and many other countries.
Melamine is used in making plastics and is high in nitrogen, which makes products appear to have a higher protein content.
Health experts say sustained use can cause kidney stones and renal failure, especially among the young.
