A prison officer was taken to hospital after he intervened in an fight between two inmates.
Inter-county footballer Donal Ward suffered a shoulder injury during a scuffle when he and another officer broke up the altercation.
Ward, who is due be taking part in the GAA Championship for Roscommon next weekend, was taken to Tallaght Hospital.
It is understood his colleague suffered facial injuries in the fight, which broke out in Cloverhill Prison when one inmate on remand attacked another at around 11.30am.
Ward previously won a gold medals in the World Police and Fire Games in Belfast for boxing.