With the latest one, the total number of Covid-19 patients in the district reached 22, said Upazila Family Planning Officer Dr Md Lutfor Rahman.
He said the 47-year-old man went to Manikganj 250 Bed District Hospital with a nose sore on Friday.
Physicians got his samples tested at Bangladesh Livestock Research Institute in Savar and found those positive for the virus on Saturday.
He is now in isolation at his own residence while those who came in contact with him have been asked to stay in quarantine, Dr Rahman said.
He attended his workplace in Saturia on April 20 for the last time.
The RMG factory workers are now at high risk of being infected with the virus as most of the owners are reportedly running their factories without ensuring proper safety and hygiene for the workers.
Earlier in the day, seven RMG workers were found to be positive for the virus in Savar.
Also read: 7 RMG workers among eight test coronavirus positive in Savar
Bangladesh has so far recorded 8,790 cases and 175 deaths from the coronavirus.