Reuters reports that the recall follows media reports that some of its dumplings tested positive for the virus.

African swine fever is incurable in pigs but does not harm people. An epidemic of the disease has spread rapidly across China since August 2018, reaching 25 provinces and regions.

Dumplings, which consist of dough wrapped around meat or fish that are then boiled, fried or steamed, are a staple Chinese dish and are also a central meal for the Lunar New Year holiday.

Sanquan, one of China's top dumpling brands, said in a statement to the Shenzhen Stock Exchange that it has recalled all products suspected of contamination, specifically citing reports of contamination in three batches of pork dumplings. The company said it is cooperating with local authorities on an investigation into the reports.

The company did not confirm or deny the reports in the statement.

The Ministry of Agriculture and Rural Affairs said late Monday it has set up an inspection team to investigate the matter and asked companies involved to track the origin of pork used in the reportedly contaminated products.

Producers of pork products must strengthen controls and improve testing for African swine fever to ensure tainted pork does not enter the food processing chain, it added.

Late on Friday 15 February, the Communist Party-run Beijing News said that dozens of samples of processed pork products sold in the northwestern Chinese province of Gansu were found containing the virus.

The positive samples, confirmed by local authorities, according to the report, came from 11 different companies including Sanquan, Kedi Group and Synear.

Kedi Group and Synear could not be reached on Monday (18 February) for comment.

Another report on Friday by the Economic Observer said Sanquan products sold in Hunan province had also tested positive for the virus.

The media reports show that diseased pigs are entering the food supply chain, although it was not clear if the virus was still in a viable form.

The suspected contamination was expected to further hit pork consumption in China, as consumers worry about eating infected meat, analysts said.

"We are already in the flat demand season," said Yao Guiling, an analyst with consultancy China-America Commodity Data Analytics. "Now that brand products were reported with issues, pork consumption will be further hit."

Pork consumption in 2018 was estimated to decline by 0.5 percent because of consumer fears over safety, market research firm Euromonitor International told Reuters in late January. Overall, however, consumption will still be up slightly on the prior year at 41.3 million tonnes.

Fitch predicts a similar hit to consumption in 2019, and has revised up poultry consumption.

Other Chinese food products have also been found containing the virus in recent months, prompting Beijing to issue stricter rules for slaughterhouses including a requirement to sample batches for the virus.

Last month, frozen food firm Fujian Anjoy Foods Co. Ltd said that some of its meat balls were suspected to contain the African swine fever virus.

Sanquan, headquartered in China's central Henan province, said it was implementing further measures to test and control against African swine fever.

It added that every batch of its pork came from quality suppliers and was certified by relevant authorities.

The company's shares rose about 2.4 percent in Tuesday morning trading, having fallen about 1.7 percent on Monday.

African swine fever contamination in Chinese food products raises the chance of its spread to other countries as consumers take food with them overseas to neighbouring Japan, South Korea and Taiwan and even Australia.