The Stardust inquests have heard there is "no evidence" that arson was the cause of the fire in the 1981 disaster and that no accelerant was found during an examination of the area where the fire was first seen inside the club.
Dr Will Hutchison, a fire expert who has been retained by the coroner to give his opinion on the possible cause and origin of the fire, continued his evidence today at the Dublin District Coroner's Court.
Forty eight people died after a blaze swept through the Artane club in the early hours of 14 February 1981.
The victims were between 16 and 27 years old.
In court today, Sean Guerin, SC, representing families of the dead, said there is "absolutely no evidence" that anyone deliberately set a fire in the west alcove.
"Yes, that’s right," Dr Hutchinson told the court.
He also agreed with counsel for the families there was a "detailed evidential basis" which explains how the fire started in the hot press in the main bar and it being observed by people outside through the roof before it was then "shortly after" seen in the west alcove inside the club as dripping molten materials.
Earlier Mr Guerin said it was clear that there was a "full Garda technical team" who conducted a "methodical and painstaking" sifting operation of the west alcove over a three day period.
He said the samples taken were analysed and that no accelerant was found.
Dr Hutchinson said that was correct and said the samples taken "would most likely have been picked wisely" by the officers.
Mr Guerin put it to the witness that when the jury come to assess the fact that no accelerant was found, they will have to do so with the knowledge that the "detailed" examination was carried out by a full garda team who were technically qualified.
"Yes," replied Dr Hutchinson.
He also agreed that if the jury are satisfied with witness accounts from those outside the club who have said they saw fire coming from the roof of the club before the fire was first seen inside the ballroom, then there must have been sufficient fuel in the roof space to fuel the fire they saw.
Mr Guerin pointed to evidence of Fiacre Mulholland, who in 1981 worked for a cladding supplier company.
He told the inquests last June that he saw expanded polystyrene known as polyzote used in the coating of some of the warm air heating ducts that ran in the ballroom's roof space.
Dr Hutchinson said he would accept that polyzote would "constitute substantial fuel" for a fire.
The court heard how once ignited it would give off substantial noxious fumes and heat and would generate molten and burning liquid.
Earlier, Mr Guerin put it to Dr Richardson that looking across "all of the technical reports", that there is no mention of polyzote ‘at all.’ He said it appeared to be the case that no one was actually looking for it.
"There is no indication that anyone did look for it," Dr Richardson said.
"To some extent … you can only find what your looking for," said Mr Guerin.
"Yes," replied the witness.
Earlier in the week, Dr Hutchison told the jury that he had considered and ruled out the fire starting in the roof space, saying there was no significant fire load or fuel in that area.
The inquests continue on Monday.
