A man indecently touched himself in front of a schoolboy during a train journey from Dewsbury.
The man watched pornography on his mobile phone and performed an indecent act while the train travelled between Dewsbury and Cottingley on Friday afternoon.
British Transport Police today released CCTV images of a man they would like to speak to in connection with the incident on the 3.31pm Huddersfield to Leeds service.
Det Con Mick Kelly said: “The 15-year-old boy was heading home after school when he boarded the train at Mirfield and sat in the first carriage on his own.
“A man boarded the train at Dewsbury and sat next to him. He then began to watch pornographic material on his mobile phone whilst performing an indecent act on himself, only stopping when the conductor passed through the carriage.
“If you recognise the man pictured, who we believe left the train at Leeds, we would like to hear from you as you may be able to assist our investigation.
“Incidents like this are very rare, but this was clearly a very distressing and intimidating experience for the young passenger. This behaviour will not be tolerated”
Phone BTP on freefone 0800 40 50 40 quoting reference B2/ NEA of 28/01/2013, or Crimestoppers anonymously on 0800 555 111.