This is a youth police want to speak to in relation to a train robbery where a victim was threatened with being stabbed in the heart.

The incident took place on a train travelling between Streatham and Tulse Hill just after 5pm on December 20.

A 26-year-old man was approached by the robber who threatened to stab or “shank” him if he failed to hand over money and his mobile phone.

Police said no knife was produced, but the victim, in fear of being injured, handed over his phone and £20.

When the train pulled into Tulse Hill the youth handed back the mobile phone and got off the train.

The youth is Afro-Caribbean, believed to be aged between 14 and 17, is about 5ft 5in tall, and was wearing a distinctive woollen hat.

He was wearing a dark coloured jacket and light blue jeans.

Anyone with information to assist police is asked to contact the British Transport Police on 0800 405 040.