Reaction: The Ulster Unionist Party said Judge Cory's finding reignited suspicions concerning Garda collusion with the IRA.
Newry and Armagh Assembly member, Mr Danny Kennedy said: "It is clear from Judge Cory's recommendations that there is a strong suggestion that there was collusion between the IRA and the Garda in the murders of Supt Bob Buchanan and Chief Supt Harry Breen in 1989.
"This confirms our worst fears over many years and it is right and proper that the matters be fully investigated to ascertain just who was involved in the murders."
The Labour leader, Mr Pat Rabbitte said: "The publication of the Cory reports into the murders, by the Provisional IRA, of Lord Justice Gibson and Lady Gibson on the one hand, and Chief Supt Breen and Supt Buchanan on the other, is to be welcomed.
"The reports are clear, simple and accessible, and Judge Cory deserves thanks for that.
"It is quite clear from reading the reports that there are compelling grounds for a public inquiry, along the lines recommended by Judge Cory and with full powers to procure documents and compel witnesses, into the murders of Chief Supt Breen and Supt Buchanan, and into the extremely serious possibility that those murders were facilitated by collusion between some members of the Garda Síochána and the Provisional IRA.
"I call on anyone who has evidence to give to come forward. The murders of these two policemen in 1989 were particularly brutal crimes, carried out in a way that betrayed cruelty and callousness.
"There is a particular onus on those who have demanded public inquiries into other murders, in respect of which reports from Judge Cory are still awaited, to ensure that there is no obfuscation about urging their members and supporters to give the Breen and Buchanan inquiry their full co-operation."
Sinn Féin and the SDLP, meanwhile, called on the British government to publish the Cory findings into the killing of solicitor Pat Finucane, the killing of Robert Hamill who was kicked to death by a mob in Portadown, Co Armagh in 1997, the killing of LVF leader Billy Wright in 1997 at the Maze prison, and the killing of Lurgan solicitor Rosemary Nelson in 1999. Five human rights organisations - Amnesty International, British-Irish Rights Watch, the Committee on the Administration of Justice, Human Rights Watch and the Lawyers Committee for Human Rights - have also called for the reports to be published.
A spokesman said yesterday there was "no basis for any further delay in making the reports public" as the delay was causing distress to the families. Yesterday Mr Finucane's son, Michael, told the BBC: "My family feel extremely let down. We're on the receiving end of yet more bad faith and delay.
"The British government needs to realise that this issue will not go away.
"It needs to publish the report now and immediately establish a public inquiry if recommended by the judge."