Three more babies died at the Malda Medical College and Hospital on Thursday, taking the total number of crib deaths in the facility to 16 in the past three days.
Hospital sources said three newborns have died due to respiratory problems, low weight and infection.
Seventy-five babies are receiving treatment at the hospital. The babies hail from Chanchol, Habibpur and Pakna areas of the district.
Meanwhile, the police has ordered a DNA test on the baby whom the parents claimed was swapped in the hospital.
A woman identified as Tuntuni Choudhury of village Meherapur claimed that she gave birth to a "boy" on Wednesday and the same was conveyed to her by the attending nurses. Her husband subsequently filed an FIR with the English Bazaar police station.
Hospital authorities, however, maintained that the woman gave birth to a girl child and not as claimed by the parents.