A young woman was raped near Ascot Station after the Royal Ascot racing festival took place.
Thames Valley Police issued an appeal saying the victim, aged in her 20s, was approached by a man between 11pm and 11.30pm on June 21 who then attacked her.
The offender in his mid-20s has been described as a white male of average height and of a slim build. He was dressed in "a black or dark hooded top, with the hood up" and was riding a dark coloured bike "that may have had yellow detail on it".
The incident is said to have taken place just hours after thousands attended Royal Ascot at the nearby racecourse on Friday, before racegoers returned to the event the next day.
Thames Valley Police have since confirmed that patrols in the area have been increased in response to the assault. The force said the victim is being supported by specially trained officers.
The appeal read: “Thames Valley Police is appealing for witnesses following a rape that happened in the town of Ascot. Between 11pm and 11.30pm on Friday (21/6) a woman was walking on a footpath near Station Hill, when she was approached by a man who then raped her. No one has been arrested at this time."
Investigating officer Detective Inspector Liam Butler added: "We are investigating this concerning incident and have been making extensive enquiries.
“Patrols in the area have been increased for reassurance. We are asking for the public’s assistance and would request that anyone with information to please come forward.
“If you recognise the individual described who may be known to the Station Hill area, or if anyone was driving in the area between 11pm and 11.30pm and has dash-cam footage, please get in touch."
Anyone with information is urged to contact Thames Valley Police on 101 quoting reference 43240293544. Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.