Documents held by solicitors representing Donegal publican Frank McBrearty snr could provide evidence to test his credibility and clear the name of former detective sergeant John White, the Morris tribunal heard.
The tribunal heard an application for lawyers representing Mr White to seek discovery of documents held by Mr McBrearty's solicitor, David Walley, over which privilege is claimed.
Cormac Ó Dúlacháin SC told the tribunal he was seeking notes taken by solicitor Ken Smyth at District Court prosecutions of Mr McBrearty and at his family business in the late 1990s, and notes taken by barman John Mitchell during Garda inspections of Mr McBrearty's nightclub.
The family claims the court summonses were part of a Garda campaign of harassment after they were wrongly identified as murder suspects after the hit-and-run death of cattle dealer Richie Barron.
Mr Ó Dúlacháin said Mr Mitchell had admitted drink was served after hours in Mr McBrearty's nightclub.
Therefore the notes he took and evidence given in the district court were false.
Affidavits sworn before the High Court were also false, he said.
There was a bona fide basis for prosecutions for late-night drinking brought by his client, the barrister said.
The chairman of the tribunal said he would post his decision on the tribunal website on September 1st.
The tribunal adjourned until September 17th.