The Smithwick Tribunal yesterday said it would have to investigate the three, including Owen Corrigan, who was identified as the garda in Dundalk suspected of informing the IRA that Chief Superintendent Harry Breen and Supt Bob Buchanan were in the station.
The inquiry also named two other former garda sergeants — Leo Colton and Finbarr Hickey — as being the subject of rumours concerning collusion with republican paramilitaries.
“These three people must be investigated, not least so that if they are innocent, their names can be cleared,” said tribunal senior counsel Mary Laverty.
Corrigan was named by unionist MP Jeffrey Donaldson in 2000 under parliamentary privilege as the alleged garda who passed on information to the IRA.
Corrigan refused to make a statement to gardaí who a short time later carried out a fresh probe into allegations of collusion.
He successfully sued the Irish Mail on Sunday in 2009 over a report that linked him to the death of the two RUC officers.
Corrigan, who owns Corrigan’s pub on George’s St, Drogheda, retired from the force in 1992.
The tribunal heard that the RUC had received an intelligence report in 1985 from a “fairly reliable” source which named Corrigan as the garda passing on information to the IRA.
A British double agent, known as Kevin Fulton, claims he and his IRA commander met Corrigan in a car in Dundalk in the late 1980s. However, Ms Laverty said Fulton’s IRA commander and Corrigan deny any such meeting took place.
Fulton also claims his commander was told by another senior IRA figure that Corrigan had phoned the IRA to inform them that the two RUC officers were in the Garda station in Dundalk.
Leo Colton was identified but not named in a 1999 book Bandit Country by Toby Harnden as another garda passing information to the IRA in the late 1980s.
Another former garda, Finbarr Hickey, pleaded guilty to countersigning eight false passport application forms which ended up in the hands of three IRA members. He was sentenced by the Special Criminal Court to three years in prison. Hickey insists he did not receive any money for signing the documents, nor was he aware the passports were for the IRA. He claims he completed the forms at the request of Colton — an allegation denied by the latter.
The tribunal will resume its hearings tomorrow.