Arson was unlikely to have been the cause of the Stardust fire, according to an RTÉ programme broadcast last night.
This conflicts with the conclusion of the tribunal of inquiry into the disaster, conducted by Mr Justice Keane in 1981, that "on the balance of probabilities" the fire was started deliberately.
However, the tribunal also stated that no evidence either of arson or of accidental combustion was found.
The Prime Time programme drew on evidence from two fire consultants, Robin Knox and Tony Gillick, who re-examined all the evidence seen by the tribunal, along with further evidence concerning the contents of a storeroom near the roof of the ballroom.
Having considered a list of the contents of this storeroom, which included floor wax, table polish, toilet rolls, cloths and other flammable material, and the fact that electrical overload had been reported previously in this area, they concluded that this was the probable source of the fire.
This is a different conclusion to that arrived at by the tribunal, which considered that the fire started in the seating in an alcove, and was started deliberately.
This followed evidence to the tribunal from five expert witnesses, three of whom put forward the arson theory. One of these experts continued to defend his theory on the Prime Time programme last night.
An independent fire expert, Prof Michael Delichatsios of the University of Ulster, told Prime Time he favoured the storeroom theory, based both on its contents and its location near the roof, where the fire was seen from outside the building 20 minutes before witnesses became aware of it inside.
The arson theory was favoured by Eamonn and Patrick Butterly, owners and operators of the Stardust. On the basis of this theory they subsequently successfully sued Dublin Corporation for compensation for malicious damage, and were awarded almost £600,000.
The finding, on the balance of probabilities, that arson had been the likely cause of the fire made it possible for the Butterlys to minimise their responsibility for the fire and the resulting deaths and injuries, and made it very difficult for the families to sue them.
This was despite the fact that the tribunal also found the fact that a number of the exit doors were locked, thereby preventing people from leaving the flaming building, was a major factor in causing the deaths and injuries.
"The tribunal is satisfied that, if the appropriate precaution to ensure an efficient evacuation had existed on the night of the fire, the injuries sustained would have been unquestionably less and the death toll would almost certainly have been reduced," it said.
It found that an efficient evacuation was prevented by the fact that exits were obstructed and doors locked by chains and padlocks, and that this was the policy of the Butterlys, who were seeking to prevent people gaining entry without paying.
The locking of the exits had been brought to their attention by corporation inspectors on a number of occasions, but nothing was done about it.
" policy of keeping exit doors chained and locked until at least midnight . . . was pursued by Mr Butterly with a reckless disregard for the safety of people in the premises," Mr Justice Keane said.
"Mr Butterly's legitimate objective of preventing unauthorised persons from gaining access to the Stardust could have been readily achieved by the stationing of doormen at each of the exits, but he deliberately elected to pursue a policy which was more economical than the use of doormen and was manifestly dangerous."
Mr Justice Keane was also critical of the design of the conversion of the building, which was completed by unqualified people and in contravention of Draft Building Regulations.