One of the three former gardaí being investigated by the Smithwick Tribunal has claimed the allegations he colluded with the IRA were generated by the British authorities.
Owen Corrigan said that the allegations were made to divert attention from claims of collusion involving the northern security forces with loyalists.
Mr Corrigan, along with former sergeants Leo Colton and Finbarr Hickey, are being investigated by the tribunal to see if they colluded with the IRA in the murder of two senior RUC officers.
Chief Supt Harry Breen and Supt Bob Buchanan died minutes after leaving a meeting in Dundalk Garda Station in March 1989.
During his 14th day in the witness box, Mr Corrigan's counsel, Jim O'Callaghan, put to him several internal RUC reports dealing with the book ''Bandit Country'' by Toby Harnden, which claimed that there was garda collusion with the IRA in the murders.
These included a letter from Mr Harnden seeking assistance from the RUC in researching his book and a commitment that it would be submitted to the Ministry of Defence for prior approval through the D Notice committee.
One senior officer wrote in relation to his request that Mr Harnden "was a responsible journalist (if that is not a contraction in terms) and if such action is possible he would be a prime candidate".
He added: "Personally I would be quite keen to help him and I am confident the resulting book would be a powerful indictment of the IRA."
From other documents presented to the tribunal, some senior officers believed that Mr Harden was briefed by special branch and crime divisions within the RUC, as well as the military and other agencies.
Following publication of his book and an article by Kevin Myers in The Irish Times on the same subject, the families of Chief Supt Breen and Supt Buchanan were in contact with the RUC at the time raising issues about garda collusion.
In a subsequent interview in Washington DC with the RUC, Mr Harnden said he was told by an RUC special branch officer about a garda colluding with the IRA. He did not check the veracity of that, but accepted it.
In relation to the claim of technical information backing up the allegation of collusion, the RUC officer wrote that Mr Harnden believed this "without conformation, corroboration or checking of facts!!!"
Subsequent to the book's publication, Mr Corrigan was named as a garda mole in the House of Commons by then Ulster Unionist MP Jeffrey Donaldson.
Mr Corrigan said he did not provide a statement to the garda investigation into the claims of allegations because he did not believe the allegations.
The retired garda detective sergeant also said that he believed RUC Supt Buchanan was "irresponsible" because he frequently drove to garda stations in his own car without changing number plates.
He said everyone in the stations would be in a panic in case they would be seen talking to an RUC man.
"Bullets are not selective," the witness said.
Retired detective Jim Lane denies 'unethical' comment
A retired detective garda has told the Smithwick Tribunal that he did not say former garda colleagues were involved in "unethical" contacts with the IRA.
Jim Lane, who retired from the garda force in Dundalk 13 years ago, was recalled today to give evidence after the PSNI produced new intelligence.
That had claimed Mr Lane had said Owen Corrigan, Leo Colton and Finbarr Hickey all had inappropriate contact with the IRA.
In the witness box this afternoon, Mr Lane said he did not make such comments.