A teenage boy has been robbed while on board a train between Worthing and Angmering.
The 16-year-old boy had boarded the train at Worthing station along with a friend, when a man who was already on the service asked the victim where he was going.
The man then tried to engage the victim in a conversation about his coat, before asking him for it.
When the boy refused, the man threatened him by saying he would stab him and his friend.
He asked him for anything else he may have, and the victim handed over some tobacco.
The man then left the service at Angmering station, and he was seen to be picked up in a pale blue car, with a distinctive dent in the passenger front side.
Police have now released CCTV images of a man they would like to talk to in connection with the incident, which took place on the March 12 at 3.30pm.
Anyone with information is asked to contact British Transport Police on 0800 405040, or text 61016, quoting reference number 264 of 29/03.