The mother of the dead woman accused the rapists of killing her daughter to do away with evidence.
Two constables at the Model Town police post and two others attached to a Police Control Room van have been suspended, a police officer said.
RK Rathi, the Model Town police post in charge, had been shunted to Police Lines after the mother alleged that the police personnel misbehaved with her when she told them that her daughter was missing.
It was on Friday that the victim left her home at 8.30 am for a 12-hour factory job in Sector 63.
When the girl did not reach home until 10 pm, they conducted a search and reached the police station where the officer suggested she might have eloped with her boyfriend.
After police did not show any interest in locating the missing woman, the distraught family contacted the factory whose workers told them they saw her leave at 9.00 pm -- up till the police post.
The family got a call on Saturday morning that the daughter was lying dead alongside a road in Sector 63. She was half naked.
The mother said her daughter was gangraped before being killed.
"The autopsy report is expected within two or three days," said Senior Superintendent of Police Praveen Kumar.