The Police were called shortly before 5am on Saturday 27 October to a report that a 35-year-old woman had been sexually assaulted off London Road, Andover.
The woman is being supported by specialist officers.
A 23-year-old man from Andover has been arrested on suspicion of rape and remains in police custody at this time.
Anyone with information should call police on 101, quoting the reference number 44180403787.
Alternatively, people can call Crimestoppers on 0800 555 111, where information can be left anonymously.