The Police Ombudsman's Office has appealed for information about an incident in Armagh city on 12 April.
Police were involved in an altercation with a man and his son close to the Drumarg estate at around 5pm on that date.
It happened in a car park beside shops between the estate and the Killylea Road.
Anyone who saw what happened is asked to contact the Police Ombudsman's freephone information line on 0800 032 7880.