If ingested melamine can cause kidney stones and other potentially fatal complications.
The scare initially centred on baby formula made by China's Sanlu dairy group, but investigations have since found the contamination has extended into many other companies and products.
On Friday health officials in Taiwan said that three children had been diagnosed as suffering from possible kidney stones caused by tainted milk formula.
The news came a day after the European Union joined a growing list of regions that have banned Chinese-made food, linked to the tainted milk.
The scandal has caused widespread alarm in China, with thousands of anxious parents lining up outside hospitals across the country to have their children examined.
However Friday saw reporting of the scandal scaled back in state media amid blanket coverage of China's successful launch of its third manned space mission.