Last week, 1,159kgs of eggs produced in Hebei Province near Beijing were pulled from supermarket shelves in the capital after tests showed that the red colour of the yolks - thought by consumers to be a sign of higher quality - were caused by dye, likely added to chicken feed. Now eggs produced by Sanhu Eggs in Jiangsu Province have also been found to contain the red dye, according to state media Xinhua. The dye has also been detected in more than 6,000 chicken eggs on sale in two Metro and Carrefour supermarkets in southeast China's Fujian Province. It is not the first time that Sudan Red has been found in China's food chain. Last year, it was found in some brands of chilli oil and KFC products. However, poultry producers continue to use the dye, attracted by the higher prices on eggs with red yolks. The country's food safety body, AQSIQ, has called on local authorities to step up routine inspection and ordered relevant firms to stop production and sales. But the government has been widely criticized by national media for the latest in a series of food safety scandals. "This kind of red-yolk eggs have been on sale for several years," said the Legal Evening paper. "Why didn't these so-called experts tell consumers earlier that red yolks didn't have anything to do with more nutrition and were usually unnatural?" Tianjin newspaper the City Daily asked why the government had not taken action until exposure of use of the dye by the nation's CCTV. Beijing has also moved to ban the sale of turbot this week after the food safety officials found high levels of cancer-causing agents in the fish on sale in Beijing markets. Local media said today that other cities like Tianjin and Xi'an have also started inspections after officials in Shanghai discovered contaminated turbot on Friday. In the last week media has also reported that a northeast China food processor polished up and sold tonnes of rice, some of it 17 years old, that could be harmful if eaten.