A member of the Colombia Three is under investigation over an IRA landmine attack in which three RUC men died.
Martin McCauley, who is from Lurgan but lives in the south, is the focus of a new probe into the 1982 killings of sergeant Sean Quinn (37) and constables Paul Hamilton (26) and Allan McCloy (34), who died in an IRA explosion at Kinnego Embankment, near Craigavon, which blew their unmarked car 70ft into a field.
Ex-Bedfordshire Chief Constable Jon Boutcher announced the investigation on the 38th anniversary of the slaughter last Tuesday.
Co Armagh republican McCauley (58) has been living in Co Kildare since fleeing Colombia in 2004 where he was sentenced to 17 years in prison for training rebel Farc forces. Earlier this year it emerged that Colombia's war crimes tribunal has granted an amnesty to the three alleged IRA members involved.
In 2014 a historic conviction McCauley had for possessing weapons was quashed by the Court of Appeal, but he did not travel to Belfast for the ruling over fears he could be arrested and returned to Colombia. Unlike the UK, the south does not have an extradition treaty with the South American country.
Sunday Life understands detectives re-investigating the landmine attack are keen to speak to McCauley.
Politicians are now pushing the Irish government to help the probe and assist any future extradition attempts.
Ulster Unionist MLA Doug Beattie, in whose Upper Bann constituency the killings took place, said: "Successive Dublin governments have been very vocal in calling on the UK government to hold inquiries and inquests and to open State files with regard to legacy matters.
"It would therefore be only reasonable, and indeed the act of a friendly neighbour, if the Garda were to work with the PSNI to assist the investigation.
"This includes the arrest and extradition of suspects resident in its jurisdiction who are wanted in connection with legacy crimes and human rights abuses. The Republic of 2020 cannot be a safe haven for terrorists."
As part of a fresh appeal for information, Mr Boutcher released images of motorcycle helmets worn by the bombers, who escaped on a motorbike.
The IRA men involved were Eugene Toman (21, above) and Sean Burns (21, below), who were killed by the RUC in a controversial 'shoot-to-kill' operation two weeks later with republican Gervaise McKerr (31). A car the three were travelling in was raked with 109 bullets.
Later that month, November 1982, Martin McCauley was badly wounded after being shot by police in a Craigavon hayshed.
Michael Tighe (17), who had no connection to paramilitaries or a criminal record, was also killed during the attack.
McCauley was later convicted of possessing three rifles found in the barn. However, this was quashed in 2014 by the Court of Appeal, which ruled the evidence against him was unsafe.
Until Jon Boutcher announced his review of the case last Tuesday, relatives of murdered Sean Quinn, Paul Hamilton and Allan McCloy had almost given up hope that their killers would ever be caught.
The families said: "Never a day passes but we think of Sean, Allan and Paul. Now, however, with encouraging progress achieved, we have been given renewed hope that the culprits will be identified."
Mr Boutcher explained how huge advances in DNA techniques had led to progress.
He said: "We have made huge strides in forensic technology in the years since this happened and (Operation) Kenova is exploiting all the opportunities which were not available to previous investigations. We have made encouraging progress, but we still need people to come forward to help us complete the jigsaw and give the families of these three officers the answers they so desperately need."
The landmine murders are among several high-profile Troubles murders being re-investigated by detectives from the Operation Kenova unit.
McCauley has steadfastly refused to talk about his time in Colombia, where he was arrested in 2001 alongside republicans Jim Monaghan and Niall Connolly.
Known as the Colombia Three, they were initially cleared of training Farc rebels in the use of mortar bombs, almost identical to those developed by the IRA, to kill 79 civilians.
The trio then went into hiding before resurfacing in Ireland in 2005 after the verdict was overturned and they were each sentenced by a Colombian judge to 17 years in prison.
Last year the Colombian government granted McCauley and two co-accused an amnesty under the terms of a special peace tribunal set-up between it and FARC to end a five decade conflict.