Police in China have arrested six people and detained 41 others for allegedly distributing milk powder tainted with the same chemical which killed infants in a 2008 scandal, state media says.
Three of the six were employees of a factory in the northwestern province of Qinghai, which last month was found to have shipped milk powder contaminated with melamine to neighbouring Gansu province, the Xinhua news agency reported.
The three others arrested were suspected of involvement in hiding tainted milk products that should have been destroyed in 2008 and then selling them to the Qinghai plant, the agency said, citing food safety authorities.
Police were still investigating the cases of the 41 others in detention, Xinhua said.
Melamine is used to make plastics but has been widely and illegally added to dairy products in China to give the appearance of higher protein content.
In 2008 it was found in products from 22 Chinese dairy companies in a massive scandal blamed for the deaths of at least six infants and for making 300,000 others ill across China.
It also led to huge worldwide recalls of Chinese dairy products.
China's government has repeatedly said all tainted products were seized and destroyed after the scandal and that there was no further public health threat, but reports of contaminated products continue to trickle out.
Earlier this month, China's health ministry refuted claims that milk powder produced by the NASDAQ-listed Chinese company Synutra had caused three infant girls to grow breasts.
