The horrific sight greeted staff at the Dingle Wildlife and Seal Sanctuary in Co Kerry as they opened for business shortly before 9am yesterday.

The freshly cut seal heads had been nailed to pieces of wood, which were fixed to the sanctuary’s sign under the cover of darkness.

Red paint was used to daub the words “RIP. Cull” and “RIP. I am hungry” on the sign.

Gardaí have removed the seal heads and signs from the scene as part of their investigation.

Upset locals believe the sanctuary, which is a favourite destination for school tours, may have been targeted by individuals who say seals are destroying the local fishing industry and are demanding a cull.

Emily Butt, a volunteer at the centre, said the attack was revolting and well planned.

“This is revolting and very distressing for everyone here,” said Ms Butt.

Fishermen say that their livelihoods are threatened by a growing and hungry seal population which, they claim, is out of control and preying on scarce fish stocks.

Seals have been attacking nets on trawlers, with a monkfish catch on a Dingle trawler being destroyed 90km west of the Blaskets last week.

For the past two years, fishermen have been calling on the Government to undertake a cull to control the seal population. Last year, Bord Iascaigh Mhara and the Marine Institute commissioned a seal survey to determine if a cull is necessary. The survey is ongoing.

Seals are a protected species under Irish and European law, but there have been several reported cases of secret culls over the past decade.

One of the most notorious illegal culls occurred off the Great Blasket Islands in Kerry in 2004, when more than 50 seals, mainly young whitecoat pups, were found shot or bludgeoned to death.

Despite the outcry it caused, eight years later there is evidence that seals are still being killed as concerns over depleted fish stocks and falling prices for fishermen continue to escalate.

Officers from the National Parks and Wildlife Service will take part in an investigation.

Animal rights group Aran is offering a €5,000 reward in a bid to catch the perpetrators.

The campaign group believes further seals are in danger due to a history of seal killings along the Kerry coastline.