A specialist garda team which has been set up to re-examine the murder of Paul Quinn will seek to interview Conor Murphy about his claims that the IRA told him they were not responsible for the shocking crime.
The renewed investigation is due to commence next week following an in-depth year-long examination carried out by the Garda's Serious Crime Review Team (SCRT).
It is understood that up to 150 potential new lines of enquiry have been identified which will now be pursued by the hand-picked investigation team.
Senior security sources have revealed that gardai will make a new bid to interview Mr Murphy.
It has been learned that Mr Murphy met investigating gardai by appointment on one occasion after he made the false claims about Paul Quinn's involvement in crime.
It is understood that the top-ranking Sinn Fein member originally agreed to provide gardai with answers to "specific questions" which were deemed important to the investigation.
However, it is understood that Mr Murphy has not met the gardai since that time.
Paul Quinn's parents Breege and Stephen have also stated on several occasions that the PSNI and gardai confirmed to them that Mr Murphy did not fully co-operate with the original enquiry.
Security sources have said that they believe the murder was the work of well-known members of the IRA in south Armagh who have close links to Sinn Fein.
One source said gardai were satisfied that "it was one 100% the work of the IRA", a fact which was also established by the PSNI and the International Monitoring Commission (IMC).
Said a source familiar with the case: "The answer as to who was responsible for this crime lies in south Armagh within the ranks of the republican movement, but they are protecting themselves behind a wall of silence which is just the same as it was during the Troubles."
To date the garda investigation has resulted in more than 20 arrests including Padraig 'Paudie' Treanor, a former driver for Conor Murphy.
No one has yet been charged.
Gardai believe Paul Quinn was targeted by the IRA after he stood up to a number of local republicans including a senior figure who is heavily involved in organised crime in the area.
The problem came to a head when the murder victim beat this man's son in a fist fight.
Meanwhile, the PSNI has said it is supporting the Garda probe.
"The murder investigation into the death of Paul Quinn in 2007 is being conducted by An Garda Siochana (AGS) and being supported by detectives from PSNI," a spokesperson said.
"If anyone has information in relation to this murder they should bring it to the attention of the AGS or PSNI who will share it with AGS colleagues."
Earlier, PSNI Deputy Chief Constable Mark Hamilton also appeared on BBC Radio Ulster's Nolan show.
Asked yesterday morning if Conor Murphy should hand himself in to police over comments he had made concerning Paul Quinn, the senior officer said: "Well, I have not seen Conor Murphy's comments and those are for him to own.
"We all condemn the murder and again we would call for anyone who has information about the murder to come forward."
He was also asked if he supported Mr Quinn's mother Breege, who said Mr Murphy should come forward with the names of the IRA men he spoke to about the murder, and who denied involvement.
"I would call for anyone with information about the murder to bring it forward, of course I would," Mr Hamilton said.
He added: "I don't know what Conor Murphy knows Stephen. That's a matter for anybody who has information about the murder Stephen."