Police are investigating a 'violent threat' made to a mother and daughter on a Brighton to Shoreham bus
The incident took place some time ago between 18:00 and 19:00 on Sunday 23 December last year but police are still investigating it.
A British Transport Police spokesperson said: "A group of teenagers are reported to have been abusive to other passengers and shouting and swearing on board the service.
"When the mum and child got up to exit the bus, one said he would hurt them if they complained about the group’s behaviour.
"Officers believe the person in the image may have information which could help their investigation."
Anyone who knows the individual is asked to contact BTP by texting 61016 or by calling 0800 40 50 40 and quoting reference 43 of 24/12/18.