Police are investigating an incident on a train in Herefordshire.
The incident involved a man masturbating on board a Manchester Piccadilly to Swansea train.
The incident occurred at around 9.50pm on Sunday 7 May.
A man boarded the train at Hereford and sat adjacent to the victim. She could see the man was masturbating, before he left the train at Cardiff Central.
Officers believe the man in the image may have information which could help their investigation.
If you recognise him, or have any information, please contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 2300052279.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.