A vicious attack in which a young man suffered a suspected broken kneecap and a fractured eye socket is linked to one of the capital's most prominent INLA figures.
Details of the lump hammer attack emerged only yesterday, but it is understood to have happened at a south Dublin location a number of weeks ago.
It followed an extortion row over alleged 'taxing' of low-level drug dealers in the south inner city by the INLA figure who previously served a prison sentence for membership of the terrorist organisation.
It is understood that the victim, who is in his 20s, needed intensive treatment in St James's Hospital.
It is not believed that gardai have received a formal complaint in relation to the savage assault, but sources believe the INLA is involved in extensive extortion rackets, especially in the Tallaght and Crumlin areas.
The development comes as a bitter cash row involving a close female associate of slain burglary gang boss 'Fat' Andy Connors and his killers continues.
Some of the gang are members of the INLA.
Sources have revealed that the INLA mob in Dublin is "in turmoil" over the issue, which has even led to senior gangland figure Troy Jordan attending 'meetings' about it, according to sources.
However, it is not known if an attempted gun attack last week on an associate of Jordan in Prosperous, Co Kildare, is linked to the ongoing tensions.
Connors, a 45-year-old father-of-six, was murdered in front of his wife and children at his newly-built home on August 19, 2014.
A major INLA figure from Crumlin is a suspect for the murder, and was previously arrested and questioned about it.
Gardai are investigating whether Connors was killed by the INLA after he refused to pay up to their extortion demands and are also probing a dispute he had with a businessman.
Connors' extended Traveller gang were the chief targets of Operation Fiacla, but his murder did not end their nationwide crime spree.