Northern Ireland's public prosecutor decided in 2001 not to take action against 15 on-the-run republican prison escapees based upon the public interest, his office revealed.
The cases included a mass break-out from the Maze high-security jail near Lisburn in 1983.
A controversial Government administrative scheme informing potential fugitives that they were not wanted by police is being investigated after the Prime Minister ordered a review.
The Public Prosecution Service (PPS) said: "In 2001 decisions for no prosecution based upon the public interest were issued in respect of 15 individuals who had been identified in the administrative scheme as being on the run.
"In each of these cases the decision for no prosecution was in relation to a suspected offence of escaping from prison."
Two involved incidents in 1975, 12 in 1983 and one was from 1997, the office headed by DPP Barra McGrory said.
In September 1983 38 inmates at the Maze, the main prison for paramilitaries, escaped. One warder was killed and another seriously injured.
The PPS added: "In relation to the 12 people suspected of escape in 1983 decisions for no prosecution based on evidential grounds in respect of other offences were issued at the same time."
The contentious on-the-runs administrative scheme saw letters sent to around 190 republicans informing them they were not sought by the authorities in the UK at that moment but did not rule out future prosecutions if new evidence emerged.
Names of individuals who feared they were wanted for offences committed before the signing of the 1998 Good Friday peace agreement had been passed to the Government, mostly through Sinn Fein, asking for an assessment of their status.
Details of the plan, which was agreed by Sinn Fein and the Government in the early 2000s as part of the peace process, emerged following the collapse of a case against Donegal man John Downey.
The trial of Mr Downey, 62, for the 1982 Hyde Park IRA bomb, which killed four soldiers, was stopped because he mistakenly received one of the letters from the Government telling him he was not wanted by detectives.
In fact he was sought by the Metropolitan police but that was not communicated to him by officers in Northern Ireland.
The PPS was asked by Traditional Unionist Voice (TUV) leader Jim Allister about the directions for no prosecution involving on the runs.
He said the decisions brought into question the rule of law.
"It raises the question of how many other terrorist suspects were also accommodated over the years with 'no prosecution' directions under the guise of such being 'in the public interest'?"
Mr Allister added: "I also note that the 12 IRA escapees from the Maze in 1983 were further accommodated with directions of no prosecutions in regard to other offences on 'evidential grounds'. "How convenient.
"The entire on the runs scandal demonstrates how far the rule of law and due process was subverted for political reasons."
Lady Justice Hallett has been appointed by Prime Minister David Cameron to review the administrative scheme.
Upon the establishment of the PPS from 2005 the number of all types of criminal cases dealt with under the DPP's authority increased significantly.
The annual number of overall no prosecution decisions based on the public interest has ranged from 1,263 in 2007 to a high of 1,470 in 2009 and a low last year of 756.
The PPS said: "The overwhelming majority of decisions for no prosecution were based on insufficiency of evidence."