Beijing, July 9 (IANS) Authorities have seized 64 tonnes of raw material contaminated with toxic melamine in a dairy plant in northwest China.

Tests of samples of the milk powder showed up to 500 times the maximum allowed level of the chemical, said the quality watchdog in Gansu province, where the contaminated milk powder was first discovered.

Police traced the source of the milk powder to Dongyuan Dairy Factory, in Minhe County in neighbouring Qinghai province, Xinhua reported.

Another 12 tonnes of tainted processed milk powder products were also seized.

About 38 tonnes of the raw materials were purchased from north China’s Hebei province, the source of the toxic baby formula scandal that brought down the Sanlu dairy company in 2008, police said.

It is possible that traders had bought tainted milk that was supposed to be destroyed after the 2008 scandal, planning to process and resell it, said Wang Zhongxi, deputy chief of the quality control bureau in Gansu.

Police have detained the owner and production director of the factory.

Some milk producers have added the industrial chemical to products to fool protein content tests. The practice caused the deaths of at least six Chinese babies in 2008 and left another 300,000 infants ill.

A dairy farmer and a milk salesman were executed in November last year for their roles in the scandal which also resulted in the bankruptcy of state-owned dairy producer Sanlu.

Sanlu’s general manager, Tian Wenhua, was given a life sentence in January 2009 on charges of producing and selling fake or substandard products.