On Monday, 28 June police received a report of the abuse and criminal damage that had occurred in the vicinity of Stratford station on the evening of Saturday, 26 June.
An initial investigation was carried out but the suspect could not be identified.
Officers are now issuing an image of a woman they would like to speak to as part of their investigation.
Anyone with information is asked to call police on 101 quoting CAD 1520/27Oct. To remain anonymous contact the independent charity Crimestoppers on 0800 555 111.