Police have said they believe a fifth person could have been involved in a town centre assault.
A man and three teenagers were arrested on suspicion of wounding with intent to cause GBH, after the incident in Marshall Avenue.
A police statement said: "We now have further evidence to suggest that another man could have been involved in this incident and are appealing for information to find him."
The man and three teenagers who were originally arrested have since been released under investigation.
Officers were called to Marshall Avenue at 2am on August 24 after reports that a fight had broken out.
A 45-year-old man was treated for superficial wounds.
Anyone with information is asked to call police on 11, quoting log 37 of 24/08/18.