An investigation into a meat scandal expanded nationwide as China's top food quality watchdog launched a "thorough" probe on Monday.

China Food and Drug Administration asked local authorities to investigate all the food factories invested by U.S. food supplier OSI Group in provinces of Hebei, Shandong, Henan, Guangdong and Yunnan.

The administration will scrutinize meat sources and the process of food production in these factories. Law or regulation violators will face severe punishment.

Local TV aired a news program on Sunday alleging that Shanghai Husi Food Co., Ltd, a unit of OSI Group, had supplied products tainted with reprocessed stale meat to a string of fast food chains and restaurants across China.

Law enforcement officials have suspended production at a suburban plant of Shanghai Husi Food Co., and further investigation is underway.

New scare hits fast food chains

Shanghai has shut a food production factory for allegedly selling out-of-date meat to restaurant giants including McDonald's and KFC.

A Shanghai television channel, which first reported the allegations on Sunday night, said that workers at Shanghai Husi Food Co Ltd mixed expired meat with fresh product and deliberately misled quality inspectors from McDonald's.

Gu Zhenhua, deputy director of the city's Food and Drug Administration, said they had ordered the company to suspend production and seized food and raw materials for investigation.

Shanghai Husi Food is a subsidiary of Chicago-based food company OSI Group.

McDonald's and Yum! Brands, which owns KFC and Pizza Hut, said on Monday that they have halted buying meat products from the Shanghai supplier, and reiterated that they have zero tolerance for illegal behavior in food safety.

McDonald's asked all its outlets in China to stop using Husi products, according to a statement on the company's Chinese micro blog on Monday.

It has apologized for the absence of some meat products because of this incident and will resume the supplies when it can make sure the food materials fully comply with laws and standards.

Yum! Brands' KFC and Pizza Hut restaurants had similar responses.

Yum is China's biggest fast food company, with a market share of 5 percent last year, according to London-based researcher Euromonitor International.

McDonald's is second largest with 2.6 percent of the market.

OSI Group, which owns Shanghai Husi Food, posted a statement on is website saying: "We sincerely apologize to our customers for any problems caused and to consumers who may be affected by these events."

Shanghai authorities vow thorough probe into meat scandal

Shanghai authorities on Monday vowed transparency and timely disclosure in its ongoing probe into the alleged use of stale meat in products supplied to fast food chains including McDonald's and KFC.

Law enforcement officials had suspended production at a suburban plant of Shanghai Husi Food Co., Ltd, a unit of U.S. food supplier OSI Group, after a news program aired by local television on Sunday claimed the company was using stale meat to make products, the municipal government said in a statement. >> More 

China's latest food scandal: What we've known

Food scandal exposes loopholes

It is shocking to discover that Husi Food, a Shanghai distribution company supplying meat to international fast-food giants such as McDonald's and KFC, has long been using stale products.

An undercover investigation by reporters revealed that some ingredients seven months past their expiry date have been used. The investigation found other irregularities that go against the country's food safety laws.

The company allegedly tried to block investigation by officials of the Shanghai food and drug authority who were prevented from entering premises for an hour after arriving, arguably enough time for the company to destroy evidence and conceal problem food items. >> More

Meat supplier of McDonald's, KFC suspended

Shanghai food and drug administration has suspended the operation of a food company suspected of supplying stale meat to McDonald and KFC outlets.

Earlier on Sunday the administration had ordered that all meat products supplied by Shanghai Husi Food Co., Ltd should be taken off shelf for safety concerns.

Local media reported the company reprocessed meat products that had outlived their shelf life and supplied them to transnational fast-food chains including McDonald, KFC and Pizza Hut. >> More