A 13-year-old footpath dweller was allegedly pulled inside the taxi last night and was raped by a youth in Rafi Ahmed Kidwai Road area.
Police have arrested accused Mohammed Anwar, who was known to the victim.
An investigation into the matter has been launched, police said.
The incident is reminiscent of the Park Street rape in February 2012, when a woman was gang-raped in a moving car by youths who had befriended her in a bar and was thrown out of the vehicle. The prime accused in the case is still absconding.