A policeman who returned home in Sadar upazila here from Narayanganj tested positive for coronavirus  on Sunday.   Civil Surgeon Dr Shaymol Krishna Hawladar said the test report of the cop came from Institute of Epidemiology Disease Control and Research (IEDCR) on Sunday.   The houses of the SI and some of his neighbours were put under lockdown to prevent the transmission of the virus, he said.   The SI who returned from Narayanganj on April 14 is currently taking treatment at home, he said.      With this, a total of five people were found COVID-19 positive in the district while 602 were kept in home quarantine, he said.