Authorities in South Korea have said a North Korean defector - believed to have recently fled back to the North - had not tested positive for the novel coronavirus.

North Korea's Korean Central News Agency over the weekend had said a "maximum national emergency" was declared in Gaeseong City after a "runaway" who had secretly returned across the fortified inter-Korean border showed up with COVID-19 symptoms. 

South Korea's Central Disaster Management Headquarters on Monday said the person in question is neither in Korea Centers for Disease Control and Prevention(KCDC)'s system as a confirmed patient nor on a list of those who had close contact with one.

The headquarters added that test results of two people who had frequent contact with the said individual also turned up negative.

Authorities said the Ministry of Unification and other related agencies are in the process of confirming the identity of the suspected defector.