The incident took place on October 8 when Nisha, resident of Rajiv Colony in Sector-25 here, fell into the sewer while playing around a grocery shop, they said.
By the time locals could get the girl out of the sewer, she was dead, police said.
The girl's father Sanjay Jha has filed a complaint alleging negligence on the part of the Municipal Corporation of Faridabad (MCF).
He alleged that all the sewers on the road in that area are lying uncovered as the laying work of interlock tiles is in progress, police said.