An unlicensed kitchen waste processing plant was shut down in Songjiang District yesterday after it was exposed in the media. The plant, based at an old factory site, produced swill oil, which is usually collected from kitchen swill in gutters and drains and is recycled back onto dinner tables as edible oil, according to a TV news report.

However, the Songjiang government denied the TV report about swill oil, saying the plant's processed waste oil was sold to a factory in Minhang District for industrial purposes. "We closed the plant because it collected and processed the kitchen waste without a license," said Mei Zhifang, a Songjiang District government official. Buckets of waste oil giving off a foul stench, which had caused residents to complain, were found in the plant.

The illegal plant processed the waste oil at night. The processed oil could only be used to produce diesel oil, which the plant sold to illegal peddlers as edible oil, a former worker was quoted as saying in the TV report.

More than 200 police officers, city management officials and industrial and commercial authorities went to the factory yesterday afternoon to close it down. The law enforcement team removed the equipment and facilities and cleaned the waste oil.

The plant's owner gave authorities tips about two other factories engaged in similar illegal business in the district. The Songjiang government planned to inspect those factories soon. The city's eateries and food producers generate at least 1,000 tons of kitchen and meal waste each day and more than 10 percent of this is outside of official supervision, according to the Shanghai Greenery and Public Sanitation Bureau.