The Morris tribunal is due to sit in Donegal town this morning for the fifth day of the opening statement by lawyers.
The inquiry is investigating events involving certain members of the Garda Síochána in Donegal, including allegations of corruption, criminal behaviour, fabrication of evidence, intimidation of witnesses and involvement in the death of Raphoe cattle dealer Mr Richie Barron.
The tribunal heard on Friday claims that gardaí allegedly forged a confession by Mr Frank McBrearty Jr admitting the killing of Mr Barron in 1996.
Counsel for the tribunal Mr Paul McDermott SC said Mr McBrearty Jr was "vehement in his denial" that he ever made any confession to the killing.
The tribunal also heard of five alleged extortion telephone calls demanding money from relatives of the McBrearty family, Mr Michael Peoples and his wife, Charlotte.
The tribunal was told the calls alleged Mr Peoples had killed Mr Richie Barron, and the caller demanded up to £6,000 from him. The tribunal also heard four of these calls were traced to the home of a Garda informant and that the fifth came from a Garda stationed at Raphoe.