The authorities in the southern Chinese city of Shenzhen say that a surface sample taken from some frozen chicken wings imported from Brazil has tested positive for coronavirus.

The chicken wings were tested by local health authorities as part of routine screenings of food imports.

The Shenzhen local government said tests of every person who might have come into contact with the infected batch, as well as food products stored near it, had come back negative.

A day earlier, Chinese state media reported that coronavirus had been found in the eastern city of Wuhu on the packaging of frozen shrimps imported from Ecuador.

Both cases have raised fears that contaminated food shipments imported from abroad could cause new outbreaks of Covid-19.

Health authorities in Shenzhen said the public needed to take precautions to reduce infection risks from imported meat and seafood.

The first cluster of Covid-19 cases, found late last year, was linked to a seafood market in the city of Wuhan.