A woman has come forward after a video emerged on YouTube of a female passenger on the Tube telling a black man: "You guys used to be slaves".
The racist incident was filmed on a Jubilee Line train to Stratford in east London.
The video has been watched more than 500,000 times on YouTube.
The footage shows a woman speaking with an eastern European accent say to a black a passenger: "You have a problem because you guys used to be slaves, yeah".
Other passengers on the train can be heard saying "shut up" after the remark.
The woman adds: "I have black friends, I'm not racist."
According to the Evening Standard, police launched an investigation after the footage emerged online last week.
A woman came forward after an appeal for witnesses was launched on Friday, ITV reports.
A spokesman for British Transport Police said: "A woman, from Essex, will be interviewed in due course.
"Officers are still appealing for the person who recorded the video, and all those involved in the altercation, to come forward."
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