The Office of Public Works has said a security company will carry out a patrol of Loughcrew in Co Meath every evening, in light of recent vandalism at the historic site.

Earlier this week, it emerged that graffiti had been scratched into a stone at the Neolithic burial monument and an investigation was launched.

The OPW and the National Monuments Service said it is latest in a series of acts of vandalism at the national monument site.

Previous incidents saw the visitor counter and the guides' hilltop cabin vandalised, signage at the site removed and protective fencing - erected to comply with public health restrictions - torn down.

Condemning the acts, Minister of State with responsibility for the Office of Public Works Patrick O'Donovan said the Loughcrew cairns are passage tombs of great antiquity.

"They are part of our cultural inheritance and I am shocked that some of the ancient carved stones at this heritage site have been recklessly damaged by graffiti. I appeal to anybody with information in relation to this incident to contact the local gardaí to help find the culprits," he said.

The OPW said today that a security company will now carry out a patrol of the hilltop each evening.

They say they are working with gardaí who are aware of the anti-social incidents at the site.