One person was arrested while another was rescued from the River Slaney following an incident in Co Carlow.
It happened in the area of Town Park in Tullow on Sunday evening.
Gardaí have confirmed they were called there at about 8pm.
A 50-year-old woman was helped out of the water.
While a man, aged 56, was arrested at the scene and taken to a Garda Station in the South East under Section 4 of the Criminal Justice Act, 1984.
Investigations are understood to be ongoing.