The constable, Jamuna Prasad, who was posted at Sihani Chungi, was suspended for allegedly not taking action when the victim's father had approached him on Wednesday evening after his daughter went missing, Superintendent of Police (city), Shiv Shankar Yadav, said.
The constable allegedly did not inform his seniors about the father's complaint.
The girl was found dead next morning in a field along the Nandgram-Sihani Road opposite Mariam Nagar. Her postmortem report confirmed that she was raped before being killed.
To hide her identity, the assailants had disfigured her face.
Protests had erupted in the area after the body of the girl was found. Police had to lathicharge and fire teargas shells and rubber bullets to disperse protesters, due to which several people, including policemen, were injured.
Meanwhile, District Magistrate Aparna Upadhyaya today handed over a cheque for Rs 3 lakh as compensation to the victim's family.