Tony Blair's Northern Ireland secretary Mo Mowlam lobbied the British government's senior law officer to ask him not to prosecute a suspect to help boost peace process negotiations, the Hallett Report has revealed.
Ms Mowlam raised the case of the "high profile" individual with attorney general Lord Morris in April 1999 as talks on Northern Ireland were about to recommence.
Lady Justice Heather Hallett was asked to review the government's scheme for dealing with fugitive republicans who had fled the jurisdiction.
Her dossier, published yesterday, found "systematic flaws" in the operation of the "unprecedented" system for dealing with on-the-run republicans but concluded it was not unlawful in principle.
The judge said political pressure to resolve outstanding cases intensified following the signing of the Good Friday Agreement in 1998.
It largely ended 30 years of conflict and referred to discussions between Ms Mowlam and Lord Morris.
"She asked him to reconsider the case, taking into account the positive effect that an undertaking not to prosecute would have on the Northern Ireland peace negotiations, which were about to restart."
The attorney general made clear that any decision on prosecution would be made independently and in a quasi-judicial manner free from political pressure, the review said.
Lord Morris reconsidered the case - the alleged offence was committed before 1973 - and refused to give an undertaking not to prosecute.
To date, that individual has not been given an assurance of no prosecution.
But 187 people were later sent letters of assurance telling them they were no longer wanted by British police.
They did not rule out future prosecutions as part of a deal between Tony Blair's Labour government and Sinn Féin.