Samples collected from the packaging of a batch of imported frozen pork in Tianjin has tested positive for COVID-19, local authorities said on Sunday.
The pork was imported from Argentina and arrived in Tianjin Port on Nov 11, according to the city's disease control and prevention headquarters.
The pork has remained in cold storage since then, and none of it has entered the market, officials said, adding that they had sealed the goods and disinfected the facility.
The workers here who had exposure risks and their close contacts are currently under isolated observation and have all tested negative for coronavirus.
China has stepped up efforts to block Covid-19 through imported food.
The Ministry of Transport released a guideline in mid-November to prevent the transmission of Covid-19 through cold-chain foods imported via road and waterways.
The State Council's joint prevention and control mechanism against Covid-19 has also unveiled a plan for full-chain, closed-loop, traceable management of imported cold-chain foods.