Chinese food safety regulators are warning of a cancer-causing mildew found in peanuts and cooking oil in the southern city of Shenzhen, the official Xinhua news agency said.

It is the latest of many food safety scandals to hit China in recent years.

High doses of a carcinogenic substance, called aflatoxin, were found in peanuts sold in two supermarkets and one frozen food store, and in cooking oil in four restaurants, the Shenzhen market supervision bureau told Xinhua.

According to Reuters, "aflatoxin occurs naturally in the environment and is produced by certain common types of fungi. It can cause severe liver damage, including liver cancer."

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On Thursday, food safety officials recalled cooking oil produced by three companies in the Guangdong province — Fusheng Oil, Manyi Peanut Oil and Mabao Oil — because of fears they contained excessive levels of aflatoxin.

Xinhua reported:

The companies' storage facilities were closed and licenses revoked as authorities continue the investigation. Their factories were ordered to suspend operations.

Aflatoxin came to public attention this week after milk producer Mengniu Dairy Group said that its plant in Sichuan province had destroyed dairy products found to contain the substance.

According to Xinhua, an initial investigation into the Mengniu case found that the contamination was caused by mildewed feed given to cows.

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