Police are asking witnesses to come forward after one man robbed another between 10am and noon last Wednesday in Norman Road.
Another member of the public in a high visibility jacket is also believed to have witnessed the robbery and officers are asking that person to come forward.
A 37-year-old man was arrested on suspicion of assault and theft and released on bail.
Anyone with information is asked to report online or ring 101 quoting serial 731 of 9/12.