The Bihar chief minister Nitish Kumar ordered state police chief D.N. Gautam to undertake the probe on Thursday night even though the police headquarters had previously asked Inspector General (Patna zone) Sunil Kumar to look into the incident.
A group of men had allegedly abused, battered and then stripped a woman in her 20s in full public view at a busy road in the state capital on Thursday evening.
A police team was reportedly present at the site and watched the assault on the woman for nearly an hour before taking the culprits to the police station.
Additional Director General of Police (Headquarters) Neelmani said Assistant Sub-inspector Shiv Nath Singh, who was in charge of patrolling the area, has been suspended for not helping the woman in time.
The woman was known as resident of Jesidih, a town in the neighbouring state Jharkhand. Rakesh Kumar, a resident of Punaichak here, had lured her to Patna with a promise of providing a job to her.
Soon after she came here, Rakesh compulsory her to have sex with his friends. She ran away from the hotel where she had been staying with him for the last few days. However, Rakesh and his friends wedged up with her and attacked her.
Police have arrested Rakesh, who is said to be involved in the flesh trade.
"Police have lodged a case against Rakesh and others on the basis of the statement of the woman," an official said.
The state women's commission has asked Patna Senior Superintendent of Police R. Mallar Vizhi to submit a report on the incident.
Rashtriya Janata Dal (RJD) chief Lalu Prasad condemned the incident and said that it shows that no government existed in the state.