Detectives are investigating a report of sexual assault in Derry during the early hours of Sunday, November 18.
PSNI Detective Constable Suzanne Nicol said the woman in her late 20s was approached and sexually assaulted by an unknown male in the Great James Street area shortly before 2am.
She said: “The suspect is described as having a shaved head and was wearing a grey hoody with dark tracksuit bottoms.
“It’s believed he was driving a dark-coloured, people carrier-style vehicle.
“We know that there were a number of people and vehicles close by at the time of the assault and I am appealing for witnesses or anyone who noticed a people carrier type vehicle in the Great James Street/Little James Street area to please get in touch.”
Detectives are also keen to hear from anyone who may have captured dashcam footage.
Detectives can be contacted by calling 101, quoting reference number 241 of 18/11/18.
Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous and gives people the power to speak up and stop crime.