All key records of the dispatch of blood products to hospitals by the Blood Transfusion Service Board for the years prior to 1986 were destroyed, the tribunal heard.
The board's deputy medical director, Dr Emer Lawlor, said she believed they were destroyed in about 1995. "I accept absolutely that was something that should not have happened," she said.
Cross-examining her, counsel for the Irish Haemophilia Society (IHS), Mr John Trainor SC, said he understood the records had been destroyed piecemeal.
Dr Lawlor said as far as she knew they were destroyed in bulk. She believed there was an affidavit filed on what happened to them which could confirm this.
She added that apart from occasional exceptions no dispatch dockets were now available for the years prior to 1986. However, donor records were still available.
Asked by counsel who issued the instruction for their destruction, she said she wasn't sure but again the affidavit might help.
Counsel also asked if the board's financial records were destroyed at the same time. The tribunal heard on Monday that these were also destroyed and that no record was therefore available of the contract which the BTSB entered with Travenol to distribute its product in the Republic and get a "kickback" from the company for doing so.
Dr Lawlor said these records would have been destroyed on a yearly basis but held for a period to comply with requirements.
An IHS application to have two World In Action documentaries admitted in evidence will be made to the tribunal on Friday. The programmes, made in 1975 and 1985, deal with how commercial firms in the US collected plasma from paid donors and on the emerging risks of hepatitis and AIDS.