As China experiences a concerning spike in cases, authorities are once again pointing to imported goods as a possible source of outbreaks in the nation's north.
The city of Heihe, positioned on the Russian border, has seen a spike in cases in recent weeks, resulting in tightened restrictions as Beijing refuses to budge on its Covid-zero strategy.
The city's health authorities said on Sunday Covid-19 had been detected on the packaging of four batches of imported food from Russia, the Global Times reported.
Authorities have urged anyone who may have purchased the products, a range of confectionary items and milk powder, to disinfect them and contact local health teams.
The city has reported close to 300 Covid cases as part of its new outbreak, and is one of several outbreaks to have developed in China as it continues to struggle to eradicate the Delta variant.
Authorities say however there is no genomic link that connects Heihe with other outbreaks in the country.
Last week authorities in the city called on its residents to stop buying items imported from countries with high rates of Covid transmission. Over the weekend Russia reported its highest daily death toll of the pandemic as daily cases hit nearly 40,000.
Another city to be hit hard by the virus in recent weeks is Dalian, where health authorities have also begun to scrutinise imports in a city that is a major port and cold-chain storage hub.
Imported goods claim scrutinised by the West
Yet China's continued peddling of such a mode of transmission has been met with scepticism in the West.
Often seen as an attempt by the Chinese government and state media to deflect blame for the virus's origins, even experts have suggested the mode is highly unlikely.
Lead Chinese scientist Liang Wannian said earlier this year that cold chain transmission "plays an important part" in investigations into the virus's origins.
However, Vladimir Dedkov, who was part of the WHO-led mission to Wuhan at the start of the year, told the Associated Press the theory was far down on the list of likely sources.
"There is still controversy about the scientific merits of the coronavirus being transmitted in cold chain products, but from a practical perspective, it doesn't matter," said Mr Darin Friedrichs, senior Asian commodity analyst at StoneX in Shanghai, according to Bloomberg.
"Chinese officials and scientists believe it is possible and poses a real threat, and they are going to take action."
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