The incident occurred late last night when police brought three sex workers and a woman pimp after busting a prostitution racket to the Jawaharnagar police station, they said.
"Three sex workers from Tenali in Andhra Pradesh were rescued by the police and one woman was arrested in connection with the racket. They were all brought to the police station.
"The rescued sex workers were not arrested, as they were victims. After having meals, on the pretext of cleaning their hands they went out of police station building premises and suddenly disappeared," Inspector P Venkatagiri said.
A case was registered under section 224 (resistance or obstruction by a person to his lawful apprehension) and probe is on.