Attacks on one of the stone monuments at the Hill of Tara are religiously motivated.
That's according to author and founder of Mythical Ireland, Anthony Murphy.
The Lia Fáil stone was vandalised with spray-paint on Monday evening.
It was said to have been brought to Ireland by the Tuatha Dé Danann.
Mr Murphy told Moncrieff about its significance.
"It is said to be the stone that shrieked under the feet of the true high king of Ireland," he said.
"In other words, the candidate for kingship would stand on the stone - or place his foot against the stone - and if he was the right choice the stone would scream.
"The true provenance on the stone that stands on the Hill of Tara today is not known."
'Ark of the covenant'
Mr Murphy said the stone has different meanings for different people.
A group known as the British-Israelites came to Tara in 1899 to dig at the Ráth na Seanadh, as they believed the biblical ark of the covenant had been buried there.
They believed the prophet, Jeremiah, had come to Ireland and brought the stone that we know as Lia Fáil with him.
However they claim it is actually Jacob's Pillow: the stone mentioned in the Book of Genesis.
The Lia Fáil in Co MeathMr Murphy said the stone is also known for its unique shape.
"There are several accounts which refer to it as 'The Penis Stone'," he said.
"Of course it has been remarked that it is quite phallic in nature.
"The great challenge about Lia Fáil, in its current position, it's not the sort of stone that generally lends itself to either being stood upon or to place your foot on.
"You would imagine that Lia Fáil - as it's described in the mythology - is a stone that would be recumbent lying on the ground.
"So this only furthers the ludicrous claims of groups such as the British-Israelites."
'Religiously motivated'
He said this is the third time the stone has been damaged in the last decade.
"In 2012 somebody took an axe to it, and chipped away several pieces of it," he said.
"In 2014 somebody tipped over a bucket of paint on it.
"I suspect that all of the attacks on Lia Fáil, this is my own personal view, are religiously motivated.
"There are people who commented on my social media posts today - one individual in particular - that this thing is an abomination.
"In the eyes of the religious zealots, because this looks like a penis, this is a very overtly pagan symbol - and not the true Lia Fáil.
"Not Jacob's Pillow, not anything that could be called a sacred and holy emblem," he added.
