Police said the neighbour, identified as Sukul Tudu, rushed to the police station and surrendered after villagers chased him.
"The unconscious child was found near a field on Saturday and was admitted to Burdwan hospital in a very critical condition. She died this morning," said a senior police officer of Bolpur police station.
"Residents of the tribal-dominated Molladanga village suspected Sukul Tudu and when they confronted him, he reportedly confessed to the crime. They then chased him, but Sukul managed to rush to the police station, where he surrendered. Investigations are on," the officer added.