The Morris tribunal has heard how a Raphoe garda made a tape recording of a conversation he had with the senior officer in the county during the investigation into the death of cattle dealer Mr Richie Barron.
Mr Denis Fitzpatrick, the former chief superintendent in Donegal, said he was "sceptical" of claims in the recorded conversation that a Garda informer, Mr William Doherty, had been tortured by the IRA, having teeth pulled and his genitals burned.
On the tape, Raphoe garda Mr John O'Dowd told the then chief superintendent he had seen the gaps in Mr Doherty's mouth. However, Mr Anthony Barr SC, for the tribunal, said the missing teeth were back teeth, and unlikely to have been pulled when front teeth were more accessible.
"I was sceptical of the whole situation," said Mr Fitzpatrick. "I don't think the IRA would take out your teeth - they'd shoot you."
He added that Letterkenny district superintendent Mr Kevin Lennon had later told him: "There's nothing wrong with that guy, he's all right."
Mr O'Dowd - a former garda stationed in Raphoe - submitted a tape of the phone conversation where he told the then Chief Supt Fitzpatrick of the alleged torture.
The former chief superintendent said he was "surprised" that the call had been taped.
"I would say it was most unusual. I had never seen it happen before."
The recording was played into the record at the tribunal.
Later, Mr Justice Frederick Morris said it seemed a report to Dublin following the retraction of statements by a key witness and the arrest of a Garda informer during the investigation into the death of Mr Barron was "a sanitised version of the facts".
Mr Fitzpatrick said not everything was put in reports, but said he met with Chief Supt Dermot Jennings from Garda HQ "at a side meeting" in Sligo, where he told him that Mr Doherty was not to be trusted "because he had given us false information".
Mr Fitzpatrick also said he asked Mr Lennon on the way back from Sligo to put a planned exhumation of Mr Barron on hold because it was "too soon".
He said that before the exhumation, gardaí would need to sort out inconsistencies in statements they had taken during the Barron investigation.
Mr Fitzpatrick said Mr Lennon wrote two reports on the case before the end of 1997, and in March 1998 produced a final report.
He said he thought this report "was quite good".