The fire broke out in the early hours of Saturday, 28 December 2011, causing extensive damage to the building.
A senior member of the GAA club told Police Ombudsman investigators later that morning that he met two police officers and Fire Service investigators at the scene.
They told him there had been no sign of a forced entry and that the fire may have been caused by an electrical fault.
The next day, the club member said he met a PSNI Constable and Fire Service investigators, who told him that they were almost definite the fire had been caused by an electrical fault and that there was no indication of a crime.
However, later on Sunday, a PSNI officer watched the footage from the CCTV cameras in the clubhouse.
The officer reiterated to the same club member that the premises had not been deliberately set on fire.
The police later issued a press release to the media stating that the cause of the fire was not suspicious.
Two members of Sean Dolan's GAA Club collected the footage from police and said that within five minutes of looking at it, they saw 'shadowy figures' and a number of bright flashes from within the building.
They then contacted members of Sinn Féin, who arranged a meeting with senior police personnel, and together they viewed the footage.
The following day, Monday 30 December, 2011, police issued a fresh public statement, now saying they were treating the fire as arson.
A new Detective Sergeant was appointed to re-investigate the incident.
On 3 January 2012, the PSNI referred concerns about the effectiveness of the original investigation of the fire to the Police Ombudsman's Office.
Police Ombudsman investigators visited the scene, watched the CCTV footage, examined all relevant police documentation and spoke to police officers, fire service officers and members of the club.
The Detective Sergeant initially assigned to investigate the fire told Police Ombudsman investigators he had relied on the opinion of the Fire Service investigators to 'point him in the right direction' and could not recall suggesting to club members that the fire had been caused by an electrical fault.
He said that when he viewed the CCTV footage, he did so for a matter of minutes on a small screen and said the picture quality was not good.
The officer confirmed that he did see 'flickering' - but said he thought this was caused a car indicator light or something similar.
The Detective Sergeant said he did not conduct door-to-door inquiries, did not check the perimeter of the clubhouse and did not notice a roof tile which had been removed. He then appointed another Constable to continue the investigation.
The Constable had just been seconded to the Criminal Investigations Department.
He acknowledged to Police Ombudsman investigators that he had no experience of such incidents and said he received little or no guidance from the Detective Sergeant or more experienced officers.
The Constable said he watched the CCTV footage in its entirety, but focused mainly on the upstairs area of the clubhouse after staff had left.
He admitted he did not show the Fire Service Investigators all of the footage in his possession and that he failed to conduct a number of other inquiries before he deemed the fire not to be suspicious.
Investigators from the Fire Service were also interviewed.
One of them said that on the basis of the material shown to them by the PSNI, which they believed was all the relevant footage, they concluded that the fire had been intense and was most likely caused by an electrical fault, as there was no evidence to suggest otherwise.
The Police Ombudsman team also spoke to the Crime Scene Investigator who attended the scene. She said the area could not be properly examined, but said there were no signs of a forced entry or smell of petrol.
She said that she and the Constable initially watched the CCTV on a small monitor which had a number of small windows, each showing footage from different parts of the premises.
She said that two or three minutes in, they saw a flash and a flame coming down from the ceiling and they concluded the most probable cause of the fire was an electrical fault started in the roof space.
The Police Ombudsman, Dr Michael Maguire, recommended that the Detective Sergeant and the seconded Constable be disciplined for their failure to investigate the fire properly and that a Duty Sergeant and two Detective Inspectors also face discipline for their failure to supervise and guide the investigation.
Dr Michael Maguire said: "The initial investigation lacked leadership, direction and supervision. Police failed to conduct basic investigative enquiries such as checking the perimeter of the club house, conducting house to house inquiries, thoroughly examining the CCTV footage or seeking to speak to the 999 caller who reported the fire.
"The Detective Sergeant initially assigned as the investigating Officer had no previous experience in attending a fire of this scale and the Constable who he appointed to continue the investigation had minimal experience. Together they received insufficient guidance and assistance from more experienced officers."
*The scene of the fire and CCTV footage can be viewed here - http://www.youtube.com/watch?v=gEu2CUD77C0&feature=youtu.be