The animal sanitation inspection department of Liaoning province suspected the tainted eggs came from chicken feed and ordered an investigation into the Mingxing Feed Company as early as October 6, the Beijing News said.
The discovery of melamine-tainted eggs was announced by Hong Kong food safety authorities on October 26, with the contaminated products being traced to Liaoning's Hanwei Group, one of China's largest egg producers.
The scandal has resulted in eggs being pulled off shelves in Hong Kong and China amid growing fears that a melamine-tainted milk scandal, which has left four babies dead over 53,000 others ill, has spread to other foods.
The Beijing News further said it had found a document from the Liaoning sanitation department dated October 22 that explicitly called for a media ban.
"No media interviews on this issue shall be accepted," the paper quoted the document as saying.
Police have now taken into custody the manager of the Mingxing Feed Company, the Beij