A 15-year-old girl was walking past Torre station at around 2.30 a.m. on July 8 when she was approached by an unknown man.
When they arrived at the station, the man exposed himself and sexually assaulted her.
The victim was able to flee the scene and call police, and is being assisted by specially trained officers.
Please contact BTP by texting 61016 or calling 0800 40 50 40 and quoting reference 56 of 08/07/22.
You can also call Crimestoppers anonymously at 0800 555 111.