Eugene Cullen was serving a life sentence for the murder of Shay O’Byrne (27) in Tallaght.
Ian ‘Mad Dog’ Maloney discovered Cullen (32) was not breathing in the cell they shared in the Midlands Prison in September 2015.
Despite attempts to revive him by Maloney and staff, he was later pronounced dead from a suspected drugs overdose.
Cullen, from Crumlin, was close associate of Kinahan-linked mobster Fat ‘Freddie’ Thompson.
He had been sentenced to life in prison the previous year for the murder of Shay O’Byrne (27) in Tallaght, on March 13, 2009.
O’Byrne, was shot dead by a hooded gunman in front of his girlfriend Sharon Rattigan who is a sister of gangboss Brian Rattigan. Thompson and Rattigan were the leaders of rival gangs involved in the bloody Crumlin-Drimnagh feud.
Cullen was also the chief suspect in the murder of Gary Bryan (31), who was shot dead in front of his girlfriend in Walkinstown in September 2006
Maloney, who has around 80 convictions and is known as a violent criminal, was cellmates and close friends with Cullen at the time of his death.
In a poem he recently published on social media he said how found his pal unresponsive and tried to give him mouth to mouth.
“The morning I found Eugene passed in the cell, I ran towards the door and het the bell
“Then I started mouth to mouth, I couldn’t get a pulse so I started to shout, ue… ue please wake up, he looked so peaceful but his eyes stayed shut
“I pounded and pounded on his chest
“My eyes full of tears, I cried out get up get up
“When the officer and medics finally came through the door, we lifted Eugene up and layed him on the floor
“They worked on him for ten mins or so
“Then looked at each other and nodded no
“Hand in hand I had to let him go
“That’s the last time I saw my bro
“It just gos to show god only takes the best, by taking Eugene god past that test”
Maloney also includes a verse about how much Cullen loved his family.
“Eugene always talked highly about you
“He loved yous all so so much
“And always made sure he kept in touch
“I couldn’t be there when he was laid to rest, god bless his mother she knew her son best
“Going to his inquest it didn’t seem right
“Just looking over at his family hoping they were alright
“Now Eugene is at peace with his dad and baby Owen, waiting for his loved ones to join them at gods home.”
Maloney said it was just one of many poems he has written.
‘Mad Dog’ served a number of lengthy prison cells, including a 12-year sentence for the armed robbery of Paul Sheeran Jewellers in Dundrum Town Centre in September 2008.
While serving that sentence he was also given a prison sentence for assaulting Joey O’Brien in Charlie’s Restaurant, Dame Street, on January 4, 2009.
He previously worked as an enforcer for ‘Fat’ Freddie Thompson and was involved in the Crumlin-Drimnagh feud and other feuds in the late 2000s and early 2010s.
He was also suspected of involvement in a feud which saw a number of petrol bomb attacks and shootings in the Crumlin area earlier this year.
He was suspected of targeting two brothers who are close pals of UFC fighter Conor McGregor as part of the feud.