The incident is believed to have taken place after the woman in her 50s shared a taxi from the Glen Road to the Belsize area of Lisburn with an unknown male in his 40s.
Detectives are interested in speaking to anyone who may have been at the Glenowen Bar off the Glen Road earlier that evening from 10pm on Friday night until closing time.
They would also like to hear from the taxi driver who may have dropped off the woman at the Belsize Meadows. Anyone with information is asked to contact the police at the Rape Crime Squad at Ladas Drive in Belfast on 08456008000 or use the Crimestoppers on 0800555111.
Police said that a 40-year-old man who was questioned earlier in the week has been released on bail, pending further enquiries.