Chinese state media say most of the melamine-tainted dairy products that have resurfaced in the country recently have been destroyed and none has hit shop shelves or been exported.
Cases of melamine in milk have appeared in the past few months, some of which appear to have come from old stores of contaminated powder that was never destroyed despite a scandal that damaged the reputation of China's dairy industry, Reuters reports.
In 2008, six Chinese children died and 300,000 became ill from milk powder tainted with melamine, an industrial chemical that can give a fake positive result on protein tests.
San Lu - a Chinese dairy company 43% owned by New Zealand dairy giant Fonterra at the time - was at the centre of the scandal. San Lu has since folded.
The authorities say the tainted milk has reappeared because some dairy companies hoarded contaminated supplies and repackaged them later, the Xinhua news agency reports.
China executed two people in November last year for their role in the scandal, which further sullied the reputation of Chinese-made products following a string of health and product safety scares.
Beijing this week announced the formation of a national food safety commission, headed by a powerful vice-premier.
