Feared gangland criminal James 'Nellie' Walsh is recovering after being the victim of a serious assault behind bars.
The hitman (31), who is currently serving a sentence for shooting businessman Michael Frazer, is understood to have been slashed in the face over the weekend.
The violent attack occurred in Mountjoy Prison, and officials believe that a criminal from the Crumlin area was behind the attack.
This man, who is in his early 30s, is linked to one of the country's largest and most prolific car theft gangs.
Prison authorities believe that the thug slashed Walsh across the face with a shiv (razor), leaving him with serious but non-life-threatening injuries.
The incident is now the subject of an investigation by jail officials.
Walsh is linked to an ongoing feud in west Dublin, which recently saw two "blood brothers" killed.
Darragh Nugent (36) and John Gibson (28) were shot dead a week apart in the Clondalkin and Citywest areas respectively.
Gardai believe their murders were carried out due to both men being closely associated with Nellie.
The hitman was involved in a feud with a west Dublin crime gang, which has very close links to the Kinahan cartel.
Gardai believe the murders of Nugent and Gibson were carried out by a west Dublin crime group intent on "wiping out" Walsh's gang.
The attack has sparked fears in west Dublin, and behind bars Walsh is said to have been livid at the murder of two close associates.
Walsh's associates may now attempt to strike back and the gang is understood to have the backing of some south Dublin criminals.
The feud ignited when Nellie's rivals murdered innocent Dean Johnson (21), leading to their leader being shot dead in a revenge attack five days later.
Jason 'Jay' Carroll (39) was fatally shot once in the face and twice in the arm at his home at Cherrywood Drive, Clondalkin, in August 2013.
Following this, Nellie's associates attempted to enlist five people to murder five of their rivals at the same time.
While this did not happen, Nellie's intended targets are suspected of being behind this month's murder spree.
One of these is a burly thug (36), who was arrested at Dublin Airport by gardai investigating a separate feud-related plot. He was released without charge.
Another mobster in the suspected murder gang is a convicted crack cocaine dealer, who was one of 13 people arrested by gardai investigating the murder of Dean Johnson, who was shot dead in Harelawn Green, Clondalkin, in August 2013 - the first murder in a feud that has now claimed four lives.
In December, Nellie was sentenced to 10 years in jail in connection with a botched hit, during which he shot himself in the leg. He pleaded guilty to possession of a pistol with intent to endanger life at the Church of the Transfiguration, Bawnogue Road, Clondalkin, and attempted murder charges against him were dropped.