The Irish Seal Sanctuary is calling for swift action by the National Parks and Wildlife Service after the discovery of another four decapitated seals in Tramore, Co Waterford yesterday.
Eight dead seals were found this week in Wexford and Waterford - one near Dunmore East and one decapitated seal in Tramore.
The latest discoveries bring the total number of observed dead seals to 12.
Earlier this year two seals came ashore in Tramore with injuries consistent with gunshot wounds and had to be euthanised on the beach.
Spokesperson for the Irish Seal Sanctuary Johnny Woodlock said: "It's an evolving situation down there. Only last night, I heard there were a few dead porpoises washed in. They are also a protected species.
"I'm still awaiting photographs so I can confirm the number of dead seals."