38-year-old Arun Agarwal had allegedly raped the girl on August 5 and had threatened her that if she told about the incident to any one then he would kill her and her family members, they said.
Fearing this the girl had not disclosed anything to her family.
Yesterday the girl fell ill and was rushed to the hospital where she disclosed the matter, they said.
The girl's family members then lodged a police complaint against Agarwal with the Nischinda police station under Howrah Police Commissionerate yesterday.