It appears the 32-year-old Irishman was the innocent victim of a violent row that broke out in the Opium Beach Club in Marbella at around 1am.
Five people were taken to hospital with stab and gunshot wounds, including the Irish man who was shot in the chest, and a woman who was also shot in the body and seriously injured.
The suspected gunman was also treated in hospital after the incident which took place as South African DJ Black Coffee performed to around 4,000 fans in the Costa Del Sol resort.
The owner of the club, Javier Calle, spoke on Tuesday about the shooting that took place in his establishment, saying, "Honestly, I have no words to describe what happened.
“What I do have is pain, consternation and torment ," he revealed on his personal Instagram page.
The well-known businessman added that these are "very hard and delicate moments that no one should ever go through" and thanked all his followers and clients "for the support received, for being by our side and for staying united in this difficult time".
“We decided to make one of the best posters on the international scene, we take care of every detail of the organization and, above all, we are committed to this wonderful city, for us something that is above everything," he said.
It was reported locally how the exclusive nightclub had announced a top programme of entertainment for the summer season with names such as Tyga, Oboy, L´Algerino, Ninho Sdt and Jay 1 all scheduled to perform.
The performance of Black Coffee, "the biggest DJ in South Africa" was described by the club itself as one of the most anticipated concerts by Opium regulars.
The establishment has also released an official statement on its Instagram account to express "the pain” for the events that occurred and show its "solidarity” with those affected to whom it has wished "a quick and happy recovery".
They have reported that the business will remain closed, in agreement with the authorities, until security measures and protocols are in place "so that it is impossible for a sad event like the one that occurred to be repeated”.
Yesterday, we revealed the horror moment a man identified as the reveller pulled the gun from his trousers.
Police confirmed they were still looking for the weapon - and the man who stabbed the suspected gunman before he opened fire - after the photo was published locally.
There is no suggestion the Irish man injured in the horror incident was responsible for stabbing the shooter.
Sources at the Costa del Sol Hospital said yesterday the Irishman and a second woman shot at Opium Beach Club remained in a “serious” condition in intensive care but were improving.
The source said: “The two people in intensive care are still serious but they are evolving favourably.”
The Dutchman, suspected of shooting four people including the unnamed Irish lad and a Moroccan woman who was also rushed to intensive care, is currently being quizzed by police ahead of a court appearance after being released from Marbella's Costa del Sol Hospital on Monday lunchtime.
Spanish news website El Confidencial reported the 40-year-old, who it said was born in the northern Moroccan city of Tetuan, had allegedly shot innocent revellers caught up in the crossfire as they enjoyed a night out.
It claimed he and a 26-year-old friend who has also been arrested forced ambulance workers to take them to hospital after fleeing Opium during the stampede that followed the stabbing and shooting.
The Dutchman was held after medics at the Costa del Sol Hospital a five minute drive from the scene of the shooting informed police they were treating a person injured in a fight.
Opium Beach Club, due to reopen at lunchtime on Monday, remains closed with the search for the weapon being cited as one of the reasons.
Detectives have not ruled out the theory the gun could have been hidden inside the premises, although they are believed to be focusing on the possibility it was handed to a third person who has not yet been identified.
A police source confirmed: “The weapon used in the multiple shooting has not yet been found.
“Two people including the suspected gunman, a Dutch national aged 40, remain under arrest.
“Detectives are still hunting the man who stabbed the suspected gunman.”
A spokesman for the Costa del Sol Hospital confirmed three of the five people treated after the Opium Beach Club incident had been released.
They include two men aged 18 and 36 who suffered gunshot wounds but whose condition on Monday was not described as serious. The younger of the casualties is thought to have escaped life-threatening injuries because the bullet hit a wallet in his front pocket.
The incident that led to the stabbing and shooting followed an earlier altercation in a VIP area to the side of the stage where award-winning DJ Black Coffee, the headline act, was performing.
Witnesses said the reveller who stabbed the gunman had been escorted away from the stage by bouncers after an altercation a few minutes earlier but returned to confront him with a weapon thought to be a knife.
Felipe Juan Froilan, the nephew of Spanish King Felipe VI, was among the crowd and celebrating his 24th birthday with friends.
The drama caused a stampede with hundreds of people running towards a busy dual-carriageway outside the club and others heading for the beach below.
Marbella Town Hall spokesman Felix Romero has described the incident as a “one-off occurrence” and insisted: “Marbella is a very safe place.” Juan Rambla, vice-president of a regional nightclub association, added: “Shootings like this occur in unexpected places by someone who is not alright or by members of the public no-one wants around.”