Shoppers arriving at the Maltby Street market on Saturday morning found part of the street cordoned off whilst detectives investigated an alleged sexual assault.
It is alleged that the incident took place at about 5am. The police cordon was in place until midday.
Officers from the Metropolitan Police's Sapphire unit are investigating.
Maltby Street has become a popular Saturday morning destination for food shoppers looking for a quieter alternative to Borough Market.
For the latest local news and events direct to your inbox every Monday, you need our weekly email newsletter SE1 Direct.