Over half a billion dollars' worth of smuggled frozen meat — some of it thawed, rotting and more than 40 years old — has been seized in China, according to local reports.

"It was smelly, and I nearly threw up when I opened the door," said an official from the central Hunan province, where 800 tonnes were seized.

More than 100,000 tonnes of chicken wings, beef and pork worth up to $624 million were seized in the nationwide crackdown, the state-run China Daily newspaper said.

Poor food safety is a major concern in China, where standards are lax and scandals involving tainted products are common.

Yang Bo, the deputy director of the anti-smuggling bureau in the Hunanese capital Changsha, said smugglers would often transport the goods in ordinary vehicles, rather than refrigerated ones, to save costs.

"So the meat has often thawed out several times before reaching customers," he added.

Two gangs from the province were among 14 busted across the country.

Reports stated that the meat seized locally came from the "border area" with Vietnam, where it was "difficult to control the flow of meat".

The China Daily said smugglers bought cheap meat abroad, shipped it to Hong Kong and on to Vietnam before bringing it to the mainland.

Officials from Guangxi, a southern region bordering Vietnam, found some of the meat was "more than 40 years old", meaning it was originally packed and stored when the country was still under the rule of Communist China's founding father Mao Zedong, who died in 1976.

The seizures were not reported on the website of China's General Administration of Customs.

China was rocked by one of its biggest-ever food safety scandals in 2008 when the industrial chemical melamine was found to have been illegally added to dairy products, killing at least six babies and making 300,000 people ill.

AFP