The victim, a 21-year-old man, was on his way back from a concert with friends when he was targeted for abuse on board a London Overground train from Highbury & Islington to Willesden Junction.
Officers have conducted a number of enquiries and are now in a position to release CCTV images of three people they would like to speak to in connection with the incident, which took place around 10.30pm on Friday 31 March. Do you know who they are?
Anyone with information is asked to text to 61016 or call 0800 40 50 40 quoting reference 386 of 31/05/2017. Alternatively, ring Crimestoppers anonymously on 0800 555 111.
Photo by British Transport Police