The older man, in his 60s, died near the poolside at the leisure center in the Ballyfin Demesne Hotel in Co Laois.

The luxury hotel’s past guests include A-list stars such as George Clooney and Kim Kardashian. The violent incident happened shortly before 8pm on Tuesday.

Horrified staff discovered the man’s lifeless body and the emergency services were called. The son of the man was arrested a short time later.

He was last night [Wednesday] being quizzed over the attack and is expected to be charged or released by this afternoon. Gardaí are satisfied there was no weapon used in the brutal attack on the man, who had traveled from New York to see his son. No clear motive has been established as of yet.

While a post-mortem was being carried out last night, gardaí believe the victim may have been beaten to death. CCTV was also being viewed last night.

It is believed that the father had traveled from Manhattan in New York to Co. Laois due to concerns over his son, who had been acting erratically in the days leading up to the tragic incident.

Sources said that the victim had only arrived in Ireland on Tuesday and was dead several hours later.

"This appears to be a very sad case," one source explained.

"What gardaí know so far is that the younger man was very vulnerable at the time and had been acting quite unwell earlier in the week, which led some people to contact his father. The father came out to look after his son by all accounts and has ended up dead. There had been some roaring and shouting and then one of the members of staff went down a short time later and found the body of this man. As you’d imagine, the member of staff was highly distressed seeing this."

They added: "What we know about the deceased man and his son is that they’re from New York and are a wealthy family.

"The immediate family has of course been informed of the death and they are making arrangements to come to Laois.

"A Garda family liaison officer has been assigned to the case and is explaining things to them like when they’ll get to see the man and then what’ll happen to the younger man if he’s charged. It’s looking more and more likely this is a terrible tragedy and I don’t use that word lightly here."

With only 20 rooms available at the 614-acre estate, Ballyfin Demesne is among the nation’s most celebrated hotels, being voted as the top resort in the UK and Ireland for 2024 by Travel + Leisure readers in July.

Located at the foot of Slieve Bloom, the lavish hotel has been visited by George and Amal Clooney, as well as Kim Kardashian and Kanye West, who enjoyed their honeymoon there in 2014.

Security at the hotel remained tight yesterday; members of staff were stationed at every entrance and exit, including one used for deliveries.

Asked if the hotel would comment on the tragedy that happened on its property, we were told that "there is nobody here that can help you with that today".

Members of the public told of their shock at the incident.

Máire Prunty was walking her dog last night when she saw "a load of Garda cars coming down the road".

And regulars in the Deadman’s Inn, a pub near the entrance to Ballyfin Demesne, were talking almost exclusively about the tragedy yesterday.

One woman, who did not give her name, said: "It’s the talk of the whole country."

Independent councilor James Kelly, who went to boarding school at Ballyfin Demesne, said he was very saddened to learn of Tuesday’s incident, calling it a "terrible tragedy."

Gardaí are investigating the matter and continue to appeal for information.

* Additional reporting by Ian Begley.

** This article was originally published on Extra.ie.