Morris tribunal chairman Mr Justice Frederick Morris has said it is "disappointing" that a son of Raphoe nightclub owner Frank McBrearty snr did not show up to give evidence.
Andy McBrearty worked as a manager in his father's nightclub in 1997 and 1998, the period during which the McBrearty family claim they were subjected to a campaign of Garda harassment.
Mr McBrearty snr claims that gardaí tried to drive him out of business after his family were wrongly identified as murder suspects following the hit-and-run death of cattle dealer Richie Barron.
His son, Andy, who now lives in Chicago, was scheduled to give evidence at the tribunal yesterday covering Garda inspections of the nightclub and other incidents.
"This is very disappointing," Mr Justice Morris said. "I'm aware that the tribunal personnel have attempted to facilitate him in every way possible and today was fixed as the date where he had given an undertaking to attend. Why he has changed his mind is hard to understand. However, he is not here so we'll have to proceed without him.
"If he chooses not to attend and not to assist the tribunal that's a matter for him."
Andy McBrearty gave evidence in Castlebar two weeks ago during the High Court hearing of the civil case brought by Mr McBrearty snr against the State for loss of business.
The publican is seeking damages of €6 million for loss of business his business suffered.
Later, Sue Quinn said that her husband Paul had told her on the night he was arrested in February 1997 that drugs found in his jacket were planted there.
Mr Quinn is related to the extended McBrearty family through his sister Róisín, who is married to a nephew of Mr McBrearty snr. "I know for a fact that my husband does not do drugs," she said. "We are up here trying to claim our innocence for the last 11 years."
Sgt Joseph Hannigan said he did not know what had become of the custody record covering Mr Quinn's time in Raphoe Garda station when he was searched and drugs were allegedly found. He did recall taking a statement from Mr Quinn the following day, but did not know where it was, although he thought he had given it to Sgt John White.
Garda Phelim Moran said Mr Quinn "seemed to be jizzed up" and "was carrying on in an aggressive hyper-erratic kind of manner" when he was brought to the station.