Two files have now been sent to the Director of Public Prosecutions because of the failure of witnesses to appear before the inquiry into allegations of corruption among Donegal gardaí.
Tribunal chairman Mr Justice Frederick Morris has also said he will consider what action to take in the case of Frank McBrearty snr, who has said he will not answer any more questions.
Mr McBrearty snr gave evidence last week at the tribunal, but after reading a statement on Tuesday he walked out before he could be cross-examined by counsel representing various gardaí.
The chairman yesterday directed that a file be sent to the DPP after he was told that Gareth Friel had not appeared to give evidence the previous day. Earlier this week, the tribunal heard evidence that Mr Friel was served with a summons to appear before it.
In a statement to gardaí investigating the October 1996 death of Richie Barron, Mr Friel said he saw Mr McBrearty snr looking "serious" the night the cattle dealer died. Last week, a file was also sent to the DPP after another witness, Paul Barron, a nephew of the late cattle dealer failed to appear.