A thug suspected of involvement in the gruesome murder and dismemberment of teenager Keane Mulready-Woods was quizzed in prison by gardai for several hours last week.
The criminal, a key member of the faction at war with the Maguire mob in the Drogheda feud, was not arrested but met with officers from the Louth division, the Sunday World reported.
The gangland figure is serving a jail term for offences unrelated to the horrific murder.
He is believed to have been in the company of the chief suspect in Keane's murder - a psychopathic Dublin mobster - on the night of the killing.
The feuding thug is also suspected of involvement in serious incidents relating to the Drogheda feud.
The move by gardai followed the revelation that the jailed thug's mob bosses have fled Ireland and are in hiding abroad.
The Herald revealed that the gang leaders - two brothers from Drogheda in their 20s - are suspected to be hiding out in Spain after fleeing the country via the UK.
The brothers were due to appear in court last week on feud-related charges but failed to appear. A warrant was not sought for their arrest.
During a week of significant developments in the probe into the killing of the 17-year-old, gardai also raided the home of a secretive crime boss based in Co Meath closely associated with the psychopathic chief suspect in the killing.
It is understood CCTV equipment and phones were seized at the gang boss's Meath home.
Officers believe the crime lord, who has been on the radar of gardai since the early 2010s, was visited by the chief suspect in the teen's killing several times around the time of the slaying.
Sources say gardai are also investigating reports he was spotted drinking with the chief suspect in a Drogheda pub days after Keane was kidnapped and dismembered.
The gangster had been in control of more than 30 associates of the anti-Maguire mob involved in the Drogheda feud but is now struggling with drug addiction.
Both men had been directing the less-experienced Co Louth mob's drug enterprise, but the younger mobsters are now understood to be taking over more control.
In another development in the garda operation to smash the feuding gangs, a junior associate in the anti-Maguire mob was caught with a loaded handgun destined to be used as part of a gangland hit.
Teenager Keane was abducted in his native Drogheda on the evening of January 12. He was murdered and dismembered in the Rathmullen area of the Co Louth town the same night.
Gardai believe he was stabbed to death.
Knives and machetes believed to have been used in the murder were later found in a shed at a house in Drogheda.