The funeral takes place on Tuesday of Eugene Kelly (62), long-time campaigner for the victims of the 1981 Stardust disaster.
His brother, Robert (17), died in the fire at the Dublin nightclub along with 47 other young people in the early hours of the February 14th, 1981.
Mr Kelly died suddenly at his home in Balbriggan on Wednesday. He was among the families who gathered at Dublin Coroner's Court a week earlier for the preliminary hearing of 48 new inquests which are to be held early next year.
The inquests were ordered last year by the then attorney general Séamus Woulfe.
Mr Kelly had campaigned almost all his adult life for an inquiry that might bring answers to the families as to how and why their loved ones died.
Speaking outside the court on October 14th, he said: “Robert’s 17, he was. Now I read my brother’s coroners report and there was nothing left of him. Those people who perished in that fire deserve justice.
“I feel they’re looking down on us and giving us the strength to keep pushing and get our justice. And mark my words, we’ll get our justice.”
Antoinette Keegan, who spearheaded the Stardust families' campaign with her late mother Christine, said Mr Kelly had "fought side by side with us right through all the years".
In an online tribute she said: "Eugene Kelly you came into my family's life…you stood tall and stood by our Ma, never once did you ever let her down, it's just so sad today…I swear to my God in heaven, you will never be forgotten and we will get truth and justice." Christine Keegan died in July.
Mr Kelly is survived by his partner Martha, children Stuart, Mandy and Lyndsey, and grandchildren.