(Bloomberg) -- Chinese officials say experts have seen little to suggest that Covid-19 is spreading via non-frozen goods after a recent infection of the omicron variant in Beijing was said to be traced to overseas mail.

Experts have insufficient evidence so far on non-frozen imported goods transmitting Covid-19 to people in China, according to He Qinghua, an official with the National Health Commission, at a press conference on Saturday. Earlier this week, the Beijing Municipal Health Commission said a positive case sometimes handled international mail at work and authorities couldn’t rule out the possibility of the person getting infected through such an instance.

Further studies need to be carried out, He said. Global studies and virus control practices show the coronavirus mainly spreads through close human-to-human contact, he said. 

“Humans contracting the virus via tainted goods is not the main spreading channel, but we cannot rule out such a possibility,” he added. 

In the Beijing instance, samples taken from a package and some documents inside international mail received by the person tested positive for the virus.

Over the past year, Chinese officials and state-backed media have alleged Covid-19 was coming into the country -- and may have even originated -- from frozen food from abroad. Global health authorities have downplayed the likelihood of such transmission, with the World Health Organization and the U.S. Centers for Disease Control and Prevention saying the chance of getting Covid from frozen foods is very low. 

In November, China warned the virus could be transmitted via parcels, testing hundreds of packages of children’s clothing after three workers at an apparel factory tested positive.

Earlier this month, three cities in China’s eastern province of Zhejiang asked anyone who had bought Vietnamese dragonfruit from certain shops to report to local governments and take Covid tests after packaging from fruit imported in December tested weakly positive for the virus. Imported Chilean cherries also drew scrutiny after a small county in Henan detected the virus on the fruit.

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