The Smithwick Tribunal has been told that hours before he was murdered in an IRA ambush, a senior RUC officer told a colleague that he believed a number of gardaí in Dundalk were passing information to republicans in return for money.
Chief Supt Harry Breen said he believed that several garda were on the payroll of Thomas 'Slab' Murphy and he specifically mentioned retired detective sergeant Owen Corrigan as an officer he did not trust.
Mr Corrigan has always denied claims that he colluded with the IRA in the two officers' murder.
Alan Maines was an RUC member and worked as a staff officer for Chief Supt Breen. He had been due to visit Dundalk with him on the afternoon of 20 March 1989 to discuss an operation targeting smuggling but did not because he had a rugby match that evening. He was replaced by Supt Bob Buchanan.
As those two men returned from a meeting in Dundalk Garda Station they were ambushed and killed by the IRA.
Mr Maines said that after the murder he mentioned this information to other senior RUC officers, including the then Chief Constable, Sir John Hermon, who dismissed the allegations.
Earlier, a former senior garda has said he believes Harry Breen and Bob Buchanan were followed after they had left a meeting at Dundalk Garda Station.
Former Chief Supt John Nolan told the tribunal that he did not consider there was a garda mole in the station who tipped off the IRA.
The tribunal is investigating if there was collusion between a garda or other State employee and the IRA, which resulted in the murders of Chief Supt Harry Breen and Supt Bob Buchanan in 1989.
Mr Nolan told the tribunal that he was surprised at the number of times Supt Buchanan had come to visit Dundalk and other garda stations.
He met Chief Supt Breen and Supt Buchanan at around 2.20pm and had a meeting in the station. It finished an hour later and the RUC officers left.
