The incident occurred between 12am and 3am on Saturday, October 24.
The victim, who is in her 30s, was walking through the alleyway connecting the bottom of Battery Hill to The Valley – next to St Luke’s Church.
She was approached by three males and was pushed to the ground. One of the men has then raped her.
If anyone heard or saw anything suspicious in this vicinity in the early hours of October 24 or if you have any information about this crime, please contact police by calling 101 and quoting reference 44200414633.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111 or report anonymously online by visiting www.crimestoppers-uk.org.