Four people were detained on Monday in connection with the Dhaula Kuan gangrape of a BPO staffer from Mizoram here last week, police said.
Describing their detention as relevant to the case, deputy commissioner of police (South) HGS Dhaliwal said: "The people detained have a criminal background and are crucial to the case."
"We are looking at all possibilities. The detentions are based on some inputs. There is a definite trail," Dhaliwal said.
The 30-year-old woman was abducted by four men and gangraped in a moving goods carrier on Wednesday last week.
She was abducted soon after being dropped along with another girl, 100 metres from her home, by her office vehicle in Dhaula Kuan area in south Delhi late in the night.
The men then drove all the way to Mangolpuri in north Delhi and dumped her there.