A woman in her 20s was attacked and raped in an alleyway in Walsall.
The attack happened on Monday between Chapel Street and Church Road, Pelsall.
Forensic experts and detectives have been examining the scene and CCTV footage is being collected as part of enquiries.
The woman is currently receiving support from specially trained officers.
A spokesman for West Midlands Police said: “We’re investigating after a rape was reported to us in Pelsall yesterday evening.
“A scene is being held between Chapel Street and Church Road, as forensic experts and detectives continue their enquiries.
“CCTV is also being retrieved and will be reviewed, and house-to-house enquiries are ongoing.
“The woman, in her 20s, is being supported by our specialist officers.
“We’d urge anyone with information to contact us via Live Chat on our website or by calling 101. Please quote 20/850122/21.”