The victim, who is in her 20s, was walking home from a night out when she noticed two men following her in the Ivy Lane area.
She continued to walk to St Martin’s Hill before entering Bab’s Hill, a field that runs adjacent to the road, where the men are alleged to have sexually assaulted her.
The incident happened between 1.50am and 2.10am on Sunday 16 July 2023.
One of the suspects is described as having brown hair and was wearing a grey jumper, black trousers and trainers. The other was wearing a black hooded top.
Witnesses or anyone with information including any CCTV, doorbell or dashcam footage that may assist the investigation is urged to call the appeal line on 01843 222289 quoting reference 46/126525/23.
Alternatively you can call the independent charity Crimestoppers anonymously on 0800 555111 or complete the online form at www.crimestoppers-uk.org