A three-month-old boy was found abandoned at a platform of the Chhatrapati Shivaji Terminus (CST) on Saturday night.
The CST government railway police said a passenger, Manoj Ashok Vishwakarma, 40, approached the police saying a woman wearing a green salwar-kurta had abandoned the boy on platform 12-13.
Vishwakarma told the police that the woman asked him to take care of the boy while she made a phone call from a public telephone booth. The woman assured him that she would return in ten minutes, but did not return for half an hour. Vishwakarma then took the boy to the CST GRP.
The police said they have registered a complaint under section 317 (exposure and abandonment of child under twelve years, by parent or person having care of it) against the unidentified woman.
"We are going through the CCTV footage of the platform and adjoining areas to identify the woman. We have also sent wireless messages to see if a missing person's complaint has been filed in the boy's name," said Somnath Tambe, police inspector, CST GRP.