Relatives of the Stardust victims are renewing their calls for a fresh investigation into the disaster, which claimed the lives of 48 people on St Valentine's Day in 1981.
At a press conference today, it was claimed that evidence not considered by the last inquiry into the disaster supports the view that the blaze started in a store room situated on a first-floor level.
Fire safety consultant Robin Knox said a letter written by a Garda Superintendent to a State Solicitor in 2008 insists the original garda map was correct and that the store room and lamp room were over a basement.
The families have always contended that there was no basement in the Stardust complex and that the store and lamp rooms were on a first-floor level.
They believe it would support their contention that the fire started in this upper area and not some distance away in the west alcove, as found by the original tribunal of inquiry in 1981.
Mr Knox today also referred to claims that eyewitnesses outside the Stardust saw flames on the roof when inside the building the fire was contained to just one chair in the west alcove.
An investigation by senior counsel Paul Coffey in 2009 criticised the original tribunal's finding that the fire was probably started deliberately. The public record was amended.