At around 9am on July 15 GMP received a report of a rape of a woman in Moss Side, South Manchester.
The woman had left a nightclub on Princess Street in Manchester City Centre in the early hours of Friday morning and, some time later, was raped at an address in Ropemaker Court.
At around 5am, the woman got into a white Audi (possibly an Audi Q7) she believed to be a taxi.
The woman was verbally and physically abused by four males who were inside the car before she was thrown out of the vehicle onto a dual carriageway around 7am.
A man in a light-coloured van stopped and helped the woman before he took her to Piccadilly bus station.
Police want to trace the man who helped the woman as he may be able to help with the investigation.
Detective Inspector Dave Moores of GMP’s Serious Sexual Offences Unit, said: “I’m appealing to the man who helped the woman in her time of need to come forward and help us with the investigation.
“He played an important part in the safety of the woman that morning.
“I’m also appealing to anyone who may have seen the woman being thrown from the car or a car of that description in the area at the time.”
Anyone with information should contact police on 0161 856 1911 or the independent charity Crimestoppers, anonymously, on 0800 555 111.