The Police Ombudsman's Office has appealed for information about a disturbance at Main Street, Newcastle, in the early hours of Sunday 23 January.
The Office is investigating how police dealt with skirmishes which broke out close to Quinn's Bar in the town shortly before 2.30am. CS Spray was used as police dealt with the disorder.
Anyone who saw what happened or has any information which they believe may assist the Police Ombudsman's enquiries is asked to contact the Police Ombudsman's Office on their freephone witness appeal line, which is 0800 032 7880.
A spokesman added, "We would be particularly keen to hear from anyone who may have captured video footage of the incident on their mobile phones."