Most of the melamine-tainted dairy products which have resurfaced in China over the past few months have been destroyed, and none has hit shop shelves or been exported, state media said on Saturday.
A number of cases of melamine in milk have appeared in the past few months, some of which appear to have come from old batches of contaminated powder that was never destroyed despite a scandal that damaged the reputation of China's dairy industry.
"Due to early discovery and timely checks, as of now, most of the tainted milk products have been recalled and destroyed, and none has entered the market or been exported," Xinhua news agency cited the National Food Safety Rectification Office as saying.
There have been no reported deaths or illnesses from the latest batches of tainted milk. About 300,000 children sought medical treatment, many with kidney stones, in the 2008 scandal.
The reason melamine, an industrial chemical which can give a fake positive on protein tests, has reappeared is that some companies "didn't fulfill the responsibilities for food safety and some violators hid tainted milk products or fabricated test reports to dodge inspections," the report said.
"In the recently reported melamine-tainted milk cases, some of the tainted milk products were apparently made of old batches of tainted milk powder slated for destruction but hoarded away instead by dairy firms and later repackaged," Xinhua said.
"The office urged related departments at all levels to thoroughly investigate the new cases and severely punish violators," it added.
China executed two people in November for their role in the 2008 scandal that further sullied the made-in-China brand after a string of health and product-safety scares.
The government this week announced the formation of a national food safety commission, headed by a powerful vice premier.