According to the hospital sources, the mother of the baby Morjina Bibi, who is mentally ill, was admitted to the hosptial on October 6 and subsequently she gave birth to a male child.
Being mentally ill, Morjina's mother Saliah hailing from Basirhat in North 24 Parganas district was allowed to accompany the infant in the gynaecology ward.
The baby's mother went to toilet when the incident took place as Saliah was keeping a watch on the baby. At that point of time, a woman approached Saliah as the baby was crying.
On the pretext of showing the baby to the doctor, the lady then took away the child but she never returned, the hospital sources added.
The Tala police station in North Kolkata was immediately informed about the missing child as the police is now investigating the matter, sources said.
The lady, who took the baby away, was not even caught on CCTV camera. The security lapses are being also looked into.