A senior gangland figure whose mob are the chief suspects in the murder of Keith Branigan was quizzed just hours after the gun attack.
The Herald has learned that the dangerous criminal, who is aged in his late 30s, was visited by gardai shortly after the gun murder.
His mob are associates of Owen Maguire and are feuding with a gang led by a 24-year-old drug dealer who was very close to Branigan.
A source told the Herald that the mob boss was not arrested over the killing but questioned about his movements at the time of the murder.
"He had an iron-clad alibi which was supported by CCTV footage. It's made gardai even more suspicious about his role in organising or carrying out the killing," a source told the Herald.
"It is standard for the usual suspects to be spoken to straight after a serious incident, which happened in this case.
"This individual made a point of being seen on CCTV for a few hours which indicates he had prior knowledge of what was going to happen."
Gardai believe the murder of Branigan is the first fatality linked to the ongoing Drogheda feud.
A number of threats have already been issued since the killing and gardai are braced for a backlash.
Additional officers attached to the Emergency Response Unit (ERU) have been deployed in Co Louth in an effort to prevent further violence.
Branigan was blasted to death in what has been described as a "cold-blooded" killing.
The 29-year-old was targeted as he worked on decking outside a mobile home in Clogherhead, Co Louth, shortly before 3pm on Tuesday.
The gunman opened fire at Branigan, with a number of stray shots also hitting two parked cars nearby.
The hit team then fled in the car toward Termonfeckin and their Lexus was burnt out in the Whiteriver area. The suspects then travelled in a black Toyota Avensis (WH 8024) which was later found burnt out in the Clonmore estate in Ardee.
Branigan was considered a mid-level member of the Drogheda crime gang involved in the feud with a Traveller mob linked to Owen Maguire, who himself was shot and seriously injured in July last year.
There had been five attempted murders before the killing with dozens more petrol bomb attacks and assaults.
The gang boss suspected of ordering this week's killing has recently been released from prison and took over the Traveller gang following his release.