CCTV images have been released following the rape of an 18-year-old woman in August.
The image is of four black men entering The Casino, Xscape, who police say could be potential witnesses.
The victim was walking over the footbridge which crosses Childs Way in the direction of Pencarrow Place between about 1am to 1.15am on Sunday, August 3.
As she walked along the footbridge, the victim walked passed a group of four black men before continuing towards Pencarrow Place.
A man then followed the victim and raped her in Pencarrow Place.
Police say the victim continues to be supported by specially trained officers and officers are continuing to work with her to bring the offender to justice.
The offender is black, in his mid thirties, athletic, between 5ft 8in and 6ft tall, with a round face. He was wearing baggy jeans. He spoke with a strong African accent.
Police would also appeal to anyone else who was in the area and saw anything suspicious to come forward.
If you recognise any of these men or have any information about the offence please contact Thames Valley Police on the 24-hour non-emergency number 101 and quote URN 555 of 4/8.