The newborn, who was reportedly being looked after by her 28-year-old cousin at the time, suffered what has been described as 'horrific' injuries in the attack that required hours of surgery.
Delhi Commission for Women (DCW) chief Swati Maliwal tweeted, 'Her heart-rending cries could be heard in the intensive-care unit of the hospital. She has horrific injuries in her internal organs.'
Maliwal further said, 'I can still hear her screams and cries...I feel horrified at this abuse of a child, I feel as if I have been raped.'
Ms Maliwal has also revealed that the DCW will be giving the mother and father of the victim 50,000 rupee ($970AU) to 'support them.'
India's Crime Records Bureau showing that between 2015 to 2016, there has been an 82% rise in child rape across the country, The BBC reports.
The statistics show that in 2016, 19,765 of cases were rape against children, up from 10,854 in 2015.
Police have confirmed that the 28-year-old man believed to be responsible has been taken into custody.