Some 4,100 pigs were culled in Hong Kong on Sunday after a second case of African swine fever virus was detected in a pig imported from mainland China.

A dead pig at the Sheung Shui abattoir in the New Territories tested positive for the virus, prompting another mass culling at the government-owned slaughterhouse, according to a government release on Friday.

Health Secretary Sophia Chan said the abattoir was closed for sanitization and she expected disinfection work to take four days before the facility reopens on Friday.

A limited supply continues at Tsuen Wan slaughterhouse.

The Hong Kong government culled 6,000 pigs across the city three weeks ago when they confirmed the first African swine fever case on May 10 in Sheung Shui slaughterhouse.

Prices of pork in local wet markets soared on Sunday following the drop in supply. In Kowloon City wet market, customers saw the price of pork belly soar from HK$60 a catty to HK$140, Ming Pao Daily reported.

The first swine fever case in the mainland was detected in August and the disease has now affected all 31 mainland provinces and led to more than a million pigs being culled, Sing Tao Daily reported.

African swine fever is highly contagious and deadly in pigs, but the virus does not affect humans. Still, the Centre for Food Safety advises people to always cook pork fully before consumption.