There was early speculation the virus arrived on the packaging of frozen-food shipments before infecting a family member - a worker at Americold - who unpacked them.
The unexpected outbreak plunged New Zealand back into lockdown after 102 days without recording a locally transmitted case of the virus.
Chinese health authorities have now revealed that traces of coronavirus have been found in frozen chicken wings and on food packaging.
A sample taken from frozen chicken wings that had arrived in Shenzhen from Brazil were reportedly contaminated with COVID-19, with an epidemiologist now warning the public to take precautions around frozen food.
Frozen shrimp from Ecuador sold in Xian also tested positive for coronavirus, according to local authorities, with the virus able to survive cold temperatures.
This means that an infected worker at a frozen food storage facility could transmit the virus to unknowing shoppers, as the food is dished out to supermarkets across the country.