Evidence has emerged that the RUC police allowed the IRA to carry out an attack on a police patrol in order to protect one or more informers.
Claims by the former British Army agent known as Kevin Fulton that he warned about the attack -- in which one RUC member died -- have been vindicated by the find.
Representatives from the office of the Police Ombudsman have found details of a tip-off recorded in a log book for March 27, 1992, the day of the attack.
The warning contained in the log book is understood to be more specific than the one which Fulton said he provided.
Early on the day in question, all RUC patrols in Newry were recalled to the station without explanation. But they were soon let back on the streets, and the attack was launched.
An arms escalation in the conflict is understood to be behind the importance of the incident to the RUC Special Branch and the British Army's FRU.
Both were aware that the IRA had developed new flashlight technology for the launch of rocket attacks, avoiding the use of radio signals which could be jammed by their patrols. The Crown forces were keen to protect the sources of their information, and it is alleged that they allowed the IRA to use the equipment despite having full knowledge of the impending attack.
Former RUC Chief Ronnie Flanagan has always maintained his men knew nothing of the IRA operation in advance of the attack. He has described Fulton as a `Walter Mitty' character who exaggerated the importance of his information.
Kevin Fulton alleged that he passed details of the rocket and the manufacturer of the device to the RUC, who could have put him under surveillance and intercepted the attack.
Kevin Fulton has also claimed that he provided sufficient information to have prevented the Omagh bombing by the breakaway `Real IRA' in 1998, in which 31 people died. The bomb exploded despite warnings from the group which the RUC said were inadequate to evacuate the area of the blast. The claims on the Omagh bombing remain controversial and led to a report by the Police Ombudsman which was highly critical of Flanagan and the RUC's approach to the attack. The victims of the Omagh bombing and families of those who died have called for a public inquiry into the attack.
Democratic Unionist MP Jeffrey Donaldson described the revelation as a major development for the family of the RUC woman who died in the Newry attack.
He said: ``Up to now the family have been told that such specific intelligence was not available.
``If this log book has emerged and if the intelligence services were aware of an imminent attack at Newry that day, it does raise a number of issues about why all police patrols were instructed to return to the station and then were sent back out again without any explanation.
``I do not want to prejudge the outcome of the investigation, but the family are entitled to know the answers to questions they have been putting for some time.''
Meanwhile, Fulton has been told that the British government will give him no extra personal protection. It was reported that the British government described the threat against Fulton outside Ireland as too low to justify the extra expense.
The decision dismayed Michael Gallagher, who lost his son in the Omagh bomb.
``If we are going to encourage people to come forward and tell the truth about what they know, we can't abandon them,'' he said. ``If this man has saved many lives, then the government should take care of him.''