The former minister for justice, Mr John O'Donoghue, is to give evidence today at the Morris tribunal, which is investigating complaints against certain gardaí in the Donegal division.
Mr O'Donoghue, now Minister for Arts, Sport and Tourism, was justice minister in the run-up to the setting up of the tribunal.
Yesterday the tribunal sat in closed session to hear the evidence of a retired chief superintendent of the Donegal division regarding top-secret Garda intelligence documents.
Former chief superintendent Seán Ginty, who retired in 1998, was last week cross-examined by suspended Supt Kevin Lennon, who is representing himself.
However, because Supt Lennon needed to question Mr Ginty about C77 documents which the Garda Commissioner had deemed confidential, further cross-examination of Mr Ginty was postponed to assist legal representatives of the commissioner. C77 forms are used by the Garda to record information on subversive activities.
The tribunal is looking into claims that alleged informer Ms Adrienne McGlinchey, together with Supt Lennon and Det Garda Noel McMahon, also now suspended, prepared explosives for use in bogus Garda arms finds.
Both officers deny the claims, and Ms McGlinchey says she was never an informer.
The tribunal has also learnt that a compromise has been reached regarding confidential C77s to which the legal team for Det McMahon sought access.
The documents will be be shown to the tribunal chairman, former High Court president Mr Justice Morris, in closed session.Meanwhile, another senior garda, Chief Supt Denis Fitzpatrick, prepared a statement over the weekend regarding his evidence.