Officials from the Yong Long factory in the southern manufacturing city of Dongguan appeared to have fled when government regulators entered the premises on Wednesday, a local government spokesperson said.

Nobody from the factory was immediately available to comment on Thursday.

Officials were investigating media reports the factory had mixed cottonseed oil and flavor-enhanced soybean oil and marketed it as peanut oil, according to a statement from the government of Zhongtang, a town in Dongguan.

Yong Long factory produces about four tons of cooking oil daily, supplying Pearl River Delta cities including Dongguan, Foshan, Guangzhou and Shenzhen, the Southern Metropolis Daily reported on Thursday, citing documents found at the factory.

The newspaper said the factory sold to Chinese food brands such as Master Kong, a household name in the instant noodle industry. It said the adulterated oil could possibly harm human reproductive cells but gave no other details.

China has struggled to rein in widespread health safety violations in its vast food processing sector. There have been several scandals involving cooking oil safety in recent years.

Police arrested 52 people at the end of last year in the southern province of Jiangxi for selling more than 2,000 tons of cooking oil dredged up from restaurant gutters.

Since July 2011, Chinese courts have sentenced at least a dozen people to jail, including one person who received a suspended death sentence, for their roles in producing or selling pork tainted with toxic chemicals.

In 2008, at least six children died and nearly 300,000 fell ill from drinking milk laced with melamine powder, an industrial compound added to milk to give misleadingly high results in protein tests.

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