The products that included the main ingredients of some Chinese delicacies such as pig ears and chicken feet contained salmonella, feed additives and veterinary drugs, says the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) website (www.aqsiq.gov.cn).

The other US companies on the ban list are Sanderson Farms Inc, Intervision Foods, AJC International Inc, Cargill Meat Solutions Corp, Van Luin Foods USA Inc and "Thumph Foods", which most likely is Missouri-based Triumph Foods.

The last three firms have been given 45 days to get their products in order. But the suspension period for the other companies has not been specified.

In late June, the US Food and Drug Administration (FDA) said it would not allow three types of farm-raised fish, as well as shrimp and eel, from Chinese suppliers to enter its market till the companies prove they didn't contain any harmful residue.

AQSIQ chief Li Changjiang called the move "unacceptable", saying China, too, detects many substandard food products from the US every year.

The AQSIQ yesterday said the local entry-exit inspection and quarantine department in North China's Shanxi Province had found excessive amounts of selenium in protein powder imported from US-based Jarrow Formulas Inc. The products have been sent back.

Excessive amounts of selenium could lead to gastrointestinal disorders, hair loss, neurological damage, cirrhosis of the liver and even death.