The confirmation came a day after the wild boar carcass was found in the central border town of Cherwon, the Ministry of Environment said.
The deadly animal disease has been detected in seven dead wild boars near the border, including two in Cherwon, about 90 kilometers north of Seoul.
South Korea has begun to mobilize hundreds of soldiers and civilians to hunt down wild boars near the border to try to contain the further spread of African swine fever.
The move comes amid rising suspicions that wild boars may be responsible for the spread of the animal disease in South Korea.
In May, North Korea reported its first outbreak of the disease at a farm near its border with China to the World Organization for Animal Health. Still, it remains unknown how the virus traveled into South Korea.
The number of wild boars killed every month has increased to around 8,000 since July, up from 4,000 over the first half of 2019, according to the environment ministry.
South Korea has confirmed 14 cases of African swine fever at local pig farms since mid-September, when the country experienced its first outbreak of the disease. So far, all of the cases have been in areas bordering North Korea.
The animal disease does not affect humans but is deadly to pigs. There are currently no vaccines nor cures for the disease.
South Korea has slaughtered and buried more than 150,000 pigs since the outbreak started. (Yonhap)