Police want to trace this man after three Erith teens were robbed at Maze Hill station.
At around 3.30pm on June 14 - the day England played Italy in the World Cup - three 15-year-old boys were waiting at Maze Hill for a train home to Erith, with their bikes, when they were approached by two men.
The boys, who were threatened, gave one of the men the cash they had on them, before boarding a train.
Detective Constable Michael Blakeburn from British Transport Police said: "The boys were terrified by the robbery and threats. I want to talk to the man in the CCTV images we have released, as he may be able to help us with the investigation."
Anyone with information should call British Transport Police on 0800 40 50 40, or text 61016, quoting reference SSUB/B11 of 11/07/2014.
Alterantively, call Crimestoppers on 0800 555 111.