Former Health Minister Barry Desmond is due to give evidence to the Lindsay Tribunal today.
Mr Desmond will be quizzed about his knowledge of the use of infected blood products to haemophiliacs.
Yesterday, a former Department of Health official challenged a claim that the former minister relied on incorrect information from the Blood Transfusion Service Board when he spoke about the matter in the Dáil in 1985.
Mr Desmond is one of a number of former health ministers due to be called to the witness box.