An alleyway off Borough High Street was closed for more than 24 hours at the weekend as detectives investigate an alleged rape in the early hours of Saturday morning.
The victim is a woman in her 20s and the offence is believed to have occurred around or before 3am on Saturday 29 June.
A Southwark Police spokeswoman said that there have been no arrests and that officers from the Met's Sapphire unit are handling the case.
For the latest local news and events direct to your inbox every Monday, you need our weekly email newsletter SE1 Direct.
7,000+ locals read it every week. Can you afford to miss out?
Read the latest issue before signing up