A former chief superintendent said he wrote a memo alleging that Raphoe publican Frank McBrearty snr was financing a campaign to discredit gardaí because private detective Billy Flynn had written defamatory letters to several officers.
"The letters in my view were offensive and defamatory in some cases," Denis Fitzpatrick said. "That was causing unease in the guards. They felt they were being targeted by these people, unjustly. I felt this was one way of reassuring them."
Mr Fitzpatrick, who was the senior garda in charge of Co Donegal, said he received complaints about Mr Flynn from members of the Association of Garda Sergeants and Inspectors.
Mr McBrearty snr claims gardaí launched a campaign to harass his family and drive his nightclub out of business in the year following the hit-and-run death of local cattle dealer Richie Barron, which was wrongly treated as a murder inquiry.
The memo directed gardaí to report any contact with Mr Flynn, Mr McBrearty or any member of his extended family or staff to the district HQ in Letterkenny.
Mr Fitzpatrick also said a meeting was arranged with lawyers representing Mr McBrearty in early 1999, to see if a settlement could be reached to end long-running District Court cases that gardaí brought against the family, but no agreement was reached.
A report on the McBrearty family, prepared by Supt Kevin Lennon, "set the tone" for an affidavit rejecting allegations by the family that gardaí were harassing them.
Frank McBrearty jnr and Mark McConnell were named as murder suspects in reply to an affidavit to the High Court by Mr McBrearty snr, who sought an injunction to stop what he claimed was excessive Garda attention to his business.
The affidavit, signed by former chief superintendent Fitzpatrick, was dated seven days after a report on the family was prepared by Supt Lennon.
"Whose decision was it to approach the reply to the complaints by criticising the people making the complaints?" tribunal chairman Mr Justice Frederick Morris asked Mr Fitzpatrick.
Mr Fitzpatrick said ultimately the responsibility for the affidavit was his, but he had left it to Supt Lennon to prepare the report on the family.
"That information probably set the tone for it all right, but I didn't instruct him to write the report in any particular fashion. I left it to himself to get whatever information he could to reply to it. That's my memory."
More than 100 summonses were served against Mr McBrearty snr, his business, his extended family and employees in 1997 and early 1998. The DPP withdrew all the charges in July 2000.
In the months following Mr White's arrival in Raphoe, the publican was served with 69 summonses for breaches of the liquor licensing laws.