A staff member was slashed when attempted to prevent a shoplifting incident at an Asda supermarket.
Police were called to the superstore, in Killingbeck Drive at 10.47pm, last night.
Staff had detained a man on suspicion of shoplifting.
Police found that a member of staff had received a cut to his arm during the incident.
He was treated at hospital and received stitches for the injury.
There was a cordoned outside the store, and in some sections of the shop, this morning as police investigate the incident.
A 22-year-old man was arrested at the scene in connection with incident. He became ill as he was being transported to police custody and was taken to hospital.
He is currently in a critical but stable condition.