The Garda sub-aqua unit, the Royal National Lifeboat Institution and the Irish Coast Guard are currently searching the water off Wicklow harbour in Wicklow town for a male swimmer.
Gardaí said they were searching the water as part of a “recovery operation”. They were alerted to a man in the water at about 4.30pm on Wednesday.
“RNLI and Coast Guard are assisting,” a Garda spokeswoman said on Wednesday night.
“The Garda sub-aqua unit are currently at scene conducting a search.”