On Wednesday, August 26 just before 7.30pm, three schoolchildren were approached by a man at the station.
The man is reported to have made inappropriate comments to the three children before a sexual assault took place.
Officers believe the man in the image may have information which could assist their investigation.
If you recognise him or have any information, please contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 2000057718.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.