Dr Nur Uddin Rashed, medical officer of Sitakunda upazila Health Complex, confirmed the matter on Monday.
He is now undergoing treatment at a hospital in Chattogrram and now doing well, said the chairman's younger brother.
The chairman has been suffering from fever since June 8. Later, samples were collected from him and sent to Bangladesh Institute of Tropical and Infectious Diseases (BITID) for testing.
The report came out on Sunday and he was confirmed to be infected with coronavirus.
The health authorities on Monday confirmed the detection of 3,099 new coronavirus patients in the span of 24 hours, raising the total number of cases to 90,619.
The death toll jumped to 1,209 as 38 more people died of COVID-19 during the same period.
Also read: Coronavirus in Bangladesh: 3,099 new cases recorded, 38 more die in 24 hrs