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.
Avon Place is a narrow alleyway alongside the British School of Osteopathy teaching centre which links Borough High Street with Swan Street.
A Southwark Police spokeswoman said that there have been no arrests and that officers from the Met's Sapphire unit are handling the case.
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