Detectives believe the vandalism is connected with the Traveller’s protest over a road barrier in Dunsink Lane, Finglas, north Dublin.
Officers say the damage to the Elmgreen public golf course in Castleknock was carried out after an agreement was made between Traveller representatives and Fingal County Council.
The vandals destroyed 11 of the 18 greens in the course and dug slogans into them reading “Open road” and “Garda scumbags”.
It is estimated the damage will cost Fingal County Council between €70,000 and €80,000.
The cost of replacing the greens is being estimated at €40,000, while the club is expected to lose €6,000 each day over the six days it is closed for repair.
The damage was carried out late on Monday night or early on Tuesday morning well after the meeting finished between Traveller representatives and Fingal County Council.
“It was done in the dead of night. No one would have heard or seen them.
“They were also very specific in where they went. None of the areas damaged were covered by CCTV,” said a garda source.
He said this was not done in the heat of the moment.
“This had to be thought out and organised. It would have taken a good while to walk 11 greens. It wasn’t done in half an hour. It was done over a considerable length of time.”
He said they had a short list of suspects. “We have a number of people we would consider to be suspects.”
Detectives say major criminals, involved in a range of serious criminal activity, operate from Dunsink Lane.
“You have a certain element, no more than you have a certain element in the settled community, that are criminally motivated.
“They don’t care too much for their own fellow beings,” said the garda.
He said the criminal gangs operated independently of each other, but are interlinked and probably cooperated in the vandalism.
Detectives say the gangs are involved in highly lucrative criminal activity including selling illegally marked diesel, selling cars to criminals and trading in firearms, fireworks, counterfeit DVDs and forged bank drafts.
“You name it, they have it. There is serious money involved,” said the garda.
Such is the wealth earned by the criminals that the Criminal Assets Bureau is carrying out its own investigations.
Gardaí have asked for anyone with information to ring Blanchardstown Station on 01-6667000 or the confidential line 1800-666111.
Pavee Point, which acted for residents on Dunsink Lane, said the vandalism was out of order.
It is understood gardaí were not happy with the decision by Fingal Council to erect the barrier.