The district’s Civil Surgeon Sheikh Fazle Rabbi Mia told bdnews24.com the result of the test on the patient’s specimens came back positive on Friday.
The person, a resident of Dampara in the city, was being treated at the isolation unit of the Chattogram General Hospital along with three others.
One of the three has tested negative while the two others await results.
Asim Kumar Nath, the supervisor at the hospital, said they were yet to be certain how the 67-year-old patient had contacted the novel coronavirus.
The person has no recent overseas travel history.
Doctors said BITID conducted tests on specimens from 31 suspected patients on Friday.
Earlier, during the daily briefing in the afternoon, the Directorate General of Health Services reported five new cases, taking the tally of known coronavirus infection in Bangladesh to 61.
As many as six of them have died while 26 others have recovered.