Representatives of the Irish Haemophilia Society are to begin giving evidence to the Lindsay Tribunal today.
They are expected to give details of how the society responded to the blood contamination crisis.
Former chairpersons of the I.H.S. are also expected to give details of how the society provided assistance for haemophiliacs who had become infected with HIV and Hepatitis C from contaminated blood products.
The current chairman of the organisation, Brian O’Mahony, will also be called to the stand.
He has said the tribunal is necessary to get closure for its members.
I.H.S. administrator Rosemary Daly, who is expected to give evidence later this week, nursed more than half of the 76 haemophiliacs who died as a result of receiving tainted blood supplies.
Last week, the tribunal heard evidence from former health ministers Barry Desmond and Rory O’Hanlon, and how they failed to adequately respond to the crisis.