Chinese authorities say they are preparing to launch a crackdown on melamine-laced milk after the scandal over tainted products, which made hundreds of thousands of children ill two years ago and damaged China's brand reputation overseas, resurfaced.

Earlier this week official media called for an intensive sweep to identify tainted products after it emerged that some of the companies involved in the 2008 scandal recycled tainted milk powder into dairy products rather than destroying it as ordered by Beijing. Melamine-laced milk powder caused at least six deaths in 2008 and made 300,000 babies ill.

Products laced with the substance – normally used in plastics and fertiliser but added to milk to boost its apparent protein content – have been found in foods in several provinces.