Officers from Leeds District Crime Team said they want to find the man who was seen by a witness on CCTV being forced to hand over money at knifepoint by four males on Mark Lane at about 1.30am on Friday.
A 16-year-old male was arrested away from the scene on suspicion of robbery. He was interviewed and later released without charge.
PC Adrian Bromley, of Leeds District Crime Team, said: “We are keen to identify the victim shown in the CCTV image so that we can progress the investigation, and we hope he will recognise himself and come forward.”
Anyone with information is asked to contact PC 3279 Bromley at Elland Road via 101 quoting crime number 13170572695.