Beijing health authorities Wednesday began a week-long crackdown on the sale and re-use of waste oil from roast duck establishments.

The inspection would focus on small and medium-sized restaurants, construction site canteens, and kebab stands, where oil was reportedly used, said a Beijing Public Health Bureau spokesman.

China Central Television (CCTV) reported Monday the waste oil exuded from the famous Peking roast duck during cooking was being illegally sold for re-use in other catering establishments.

The report said many restaurants were using the waste oil because of its cheap price and flavor. It had been made into fried dough sticks, sesame seed cakes and other popular snacks in the Chinese capital.

Health experts have warned that roast duck oil contains carcinogenic elements and could cause health problems.

The report recalled the "gutter oil," which was extracted from kitchen waste and once reportedly commonly used by small restaurants.

To respond to the increasing suspicion, Beijing Public Health Bureau Wednesday started the large-scale search for signs of recycled roast duck oil.

On Wednesday, 276 restaurants were inspected, but none were found to be using or selling "roast duck oil," said the Bureau spokesman.

The authority vowed to penalize any offenders.

(Xinhua News Agency July 15, 2010)