British Transport Police have released a CCTV image of someone they want to speak to after a teenager was allegedly robbed at Orpington Station.

The incident happened last year (November 2) at 10.10pm.

A 17-year-old boy left a train before he was followed by a man who allegedly threatened him and said he had a knife.

Police say the victim had his wrist watch stolen.

Officers believe the man in the CCTV could help with the investigation.

If you have any information contact British Transport Police on 0800 40 50 40.