BEIJING, July 9 (Xinhua) -- Food safety authorities have seized 64 tonnes of raw dairy materials contaminated with the toxic chemical, melamine, in a dairy plant in northwest China's Qinghai Province, the provincial quality watchdog said.
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 neighboring Qinghai Province.
Another 12 tonnes of processed milk powder products, also tainted, 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.
An employee of the Dongyuan Dairy Factory, Liu Xiping, sent three samples of milk powder for testing by Gansu's quality control bureau for melamine content test on June 25.
The bureau called the police after test results showed the samples had excessive levels of melamine.
A police investigation found the plant wanted to know the melamine content of the raw dairy materials they bought so as to dilute the melamine level in the milk powder before sale.
Police have detained the owner and production director of the factory.
Milk powder produced in the plant was mainly sold in east China's Zhejiang and Jiangsu provinces. Only a small amount was sold in Qinghai.
Zhejiang's food safety commission said Friday they had seized three tonnes of Dongyuan milk powder in food processing factories in the province.
The tainted milk powder, in 25-kg packages, was mainly used to produce dairy products like ice-cream, said the commission.
Most of the contaminated milk powder was still being processed and had not entered the market, it said.
Meanwhile, in Jilin City of northeast China's Jilin Province, authorities were testing samples of milk powder suspected of having excessive levels of melamine, the city's industry and commerce bureau said Thursday.
The bureau has seized more than 1,000 packages of milk powder, produced in the neighboring Heilongjiang Province, from a store after a random test found one of them had a high melamine content on June 22.
However, it did not say when the test results would come out.
Jilin's provincial quality control bureau said Thursday it would start a general check on dairy products in the province on Friday.
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 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. Altogether 21 people were convicted in connection with the scandal.