The ministry said its newest drive will be conducted in three phases, with companies first asked to conduct internal checks, followed by government checks on producers of meat, dairy and other protein-rich products that are considered "high risk".

The final stage will involve punishing companies that flout the law.

Last week the ministry acknowledged that six babies died after drinking infant formula contaminated with the industrial chemical melamine.

Almost 300,000 other infants suffered urinary problems.

"The tainted milk scandal shows illegal production of food products and the use of non-food substances are not isolated incidents," Chen Xiaohong, the health vice-minister, was quoted as saying by the China Daily newspaper.

Dairy suppliers are accused of adding melamine, a chemical used in the production of plastics, to try to disguise diluted milk by making it appear higher in protein on quality tests.

Import alert

Officials say six babies may have died after drinking tainted milk [GALLO/GETTY]
Meanwhile China has placed a 90-day import alert on 12 food items from the United States after they were found to contain a banned dye or excessive additives or preservatives.

The General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), the country's quality watchdog, said on its website that chocolate, almonds, lemon juice, cheese, herbs and healthcare tablets were among the products that will undergo increased checks.

The import alert comes as the US maintains a ban on Chinese food imports unless they are proven to be dairy-free or melamine-free, in response to the tainted milk scandal.

Earlier in the Chinese quality watchdog impounded and destroyed Italian brandy, Spanish dairy products, Belgian chocolate and seasoning from Britain.

Last year China ratcheted up inspections and tightened restrictions on food production and other industries, particularly exports, after manufacturers were found to have exported tainted cough syrup, toxic pet food and toys containing lead paint.

Despite the improvements, however, China continues to have trouble regulating its countless small and illegally-run operations, which are often blamed for introducing illegal chemicals and food additives into the food chain.