Thames Valley Police has released an e-fit image of a man it would like to identify as part of its investigation into a sexual assault.
The incident happened between 11pm and 11.30pm on Saturday February 4.
The victim, a 19-year-old woman, was walking through the underpass under the V6 Grafton Gate, next to the skateboarding site and the side of the bus station, when she was approached from behind by a man.
The man grabbed hold of her and led her away from the underpass to the stair that lead to the back of the skateboard site where he forced her to touch him inappropriately. He then let the victim go and walked off past the bus station.
Det Con John Swallow, who is investigating the incident, said: “There were skateboarders at the back of the bus station at the time of this offence and they could be crucial witnesses – they will remember the night as it snowed heavily that evening.
“I am also keen to hear from anyone else who recognizes the man in this image.”
The offender is white, around 19-20-years-old, 5ft4ins, with a slim build. He has freckles across his nose and cheekbones and dark eyebrows. He wore dark blue jeans and a waterproof jacket with the hood up which was dark blue. He also wore a dark blue scarf.
Anyone with any information about this incident should contact Det Con Swallow via the Force enquiry centre on 101.