Disclosures Tribunal Chairman Peter Charleton has been highly critical of former Garda Press Officer David Taylor.
He said it was an utter mystery as to why former commissioner Martin Callinan should have chosen him as a press officer.
After Supt Taylor was moved from the Garda Press Office in 2014, he was investigated for leaking information to journalists.
Judge Charleton describes this investigation as first class, and said that an analysis of Supt Taylor's mobile phone and email identified contacts with journalists, which he had no legitimate interest in making.
Supt Taylor later took a judicial review of disciplinary proceedings against him, swearing an affidavit which Mr Justice Charleton says was almost entirely made up of nothing but lies.
The judge says the system of garda discipline is not fit for purpose, and Supt Taylor abandoned his judicial review only because he was returned to duty.
As to the alleged smear campaign against Sergeant Maurice McCabe, Mr Justice Charleton says Supt Taylor was deceitful about the existence of text messages about the whistleblower, he goes on to say the Supt lied about text messages received by former commissioner Nóirín O'Sullivan.
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The report in quotes
The report finds that several people got the impression from Supt Taylor that he had sent malicious text messages, and they are not wrong.
In his evidence, the former Garda Press Officer said he never sent such text messages but Mr Justice Charleton accepts the evidence of TDs Clare Daly and Mick Wallace and Irish Examiner journalist Michael Clifford that they were told of the existence of such texts.
Of Supt Taylor's relationship with Ms O'Sullivan, Mr Justice Charleton says he was "suffused in bitterness against her" when the then commissioner moved him from the Garda Press Office.
The report says "his viciousness" towards Ms O'Sullivan was compounded by the trouble he was in, and he was happy to make a claim against her to help himself by lying about other people.
The report concludes that Supt Taylor's claims Mr Callinan sent slanderous texts about Sgt McCabe are false.
The report similarly finds that his claims that Ms O'Sullivan knew of the smear campaign are also false.
The report also finds that Supt Taylor spun a tale to Sgt McCabe about missing phones, texts to politicians and a trail of evidence that never existed to destroy the criminal investigation into his own behaviour.