The third case of wild Polio virus has been found in Borno state.
The two earlier ones were recorded in the state last august.
World Health Organization (WHO) in a statement warned that more cases could appear in the state.
It said the three cases were from the same strain of the disease circulating in the North East region in the past years.
The latest case concerned a two year old boy suffering from the onset of paralysis last august 6 in Monguno area of the state.