Detectives have released CCTV footage after a man headbutted a passenger queuing for coffee at London Bridge Station.
Officers from the British Transport Police have released images of the incident in a bid to identify and track down the man responsible.
The incident took place as the victim, a 34-year-old from Horsham, Sussex, waited at a Caffe Nero kiosk at the station just after 10.45pm on Friday 17 December last year.
As the victim queued to be served a man in front turned around and headbutted him.
After being held back by another passenger, the man fled and was last seen making his way down a flight of stairs towards platforms 3 and 4.
The attack left the victim with a bloodied and bruised nose.
"This was a vicious attack and we want to hear from anyone who recognises the man pictured, as he is wanted for questioning," says PC Helen Magill.
"We have made a number of enquiries as part of our investigation but to no avail so far.
"If you are the man in the footage, or recognise him, I urge you to get in touch."
Anyone with information should contact British Transport Police on 0800 40 50 40 quoting incident B4/LSA of 02/02/11.