A 22-year-old woman was raped in the early hours in Frogmoor, High Wycombe, police said.
The woman was attacked on Sunday August 10 between 2am and 2.30am, police said today.
She was walking along Temple End.
Det Con Caroline Jones, who is leading the investigation, said: "I urge anyone who was in the area at the time who saw something suspicious, or anyone who knows who committed the crime to contact me at High Wycombe police station on 0845 8 505 505."
Anyone who wishes to remain anonymous can contact Crimestoppers on 0800 555 111.
