The 17-year-old victim was attacked and robbed at knifepoint at about as he walked down a ginnel between Dixon Lane and Henry Avenue in Wortley.
A gold-coloured iPhone 6 that had been given to him by a children’s cancer charity was stolen in the robbery at 5pm on Monday, March 7.
The suspect, described as white, aged 19 to 20, slim, about 5ft 11ins tall, with a spotty complexion and a scruffy beard, rode off on a black mountain bike along Henry Avenue towards Kellet Road.
He was wearing a black coat with a hood, black tracksuit bottoms and had a black drawstring bag on his back, which had a white Newcastle United logo on it.
Detective Constable Grant Lee, of Leeds District Crime Team, said: “Despite an excellent response from the public to our previous appeals for information, we have not yet been able to identify the suspect.
“We have worked with the victim to produce an e-fit image and we believe it will be a good likeness of that person.
“We are asking people to put that image together with the physical description, the Newcastle United bag and the CCTV of him riding off on a bike and contact us if they think they know who it might be.
“This was a really frightening experience for the victim who already has enough to cope with and we remain determined to do all we can to find the person responsible.”
Anyone with information is asked to contact DC 1421 Lee at Elland Road via 101 quoting crime number 13160101094 or call the independent charity Crimestoppers anonymously on 0800 555 111.