British Transport Police (BTP) is investigating after a 33-year-old homeless and deaf woman was assaulted at Wanstead Underground train station.
Officers have released CCTV images of a woman they want to speak to about the incident, on Saturday, 28 February.
PC Elspeth Cook, investigating, said: "At approximately 8.30pm, the victim was at the entrance to Wanstead Tube station when she was physically attacked by a woman.
"The aggressor left the scene, making her way into the station and down the escalators with a man."
BTP officers were on the scene in a matter of minutes but the suspect had left the station.
Officers are now appealing for the public's help identifying a woman they want to speak to from CCTV images.
PC Cook added: "I need to know who this woman is, as I believe she holds vital information about what happened that evening. If you know who she is, or have any other information that could help, please get in touch.
"This was a seemingly unprovoked assault on a vulnerable member of the community – the person responsible needs to be caught and held to account for their actions."
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