Detectives searched his home after the incident with the binman and discovered two handguns including a loaded glock as well as a machine pistol.
Ammunition and other serious crime paraphernalia was also seized at the suspect's house. However, the individual in question had already fled his home.
The Herald understands the man was previously questioned by gardai probing the gruesome murder of his former close pal, rapist James Nolan. The 46-year-old was murdered and his body cut into pieces and dumped in the Irish Sea.
The crime might never have been revealed except that a severed arm was discovered at Dollymount Strand in February, 2011, which extensive DNA tests showed belonged to Nolan.
The suspect in the threat to the binman was arrested by detectives probing the Nolan murder four months after the grim discovery was made but was later released without charge. Sources say that he "knew James Nolan extremely well and was in a bitter financial dispute with him".
It is understood Nolan received a cash windfall after his release from prison in November, 2010.
Detectives believe that he refused to help out his former associate financially and a major row occurred.
Like Nolan, the suspect has spent much of his life in jail for offences such as armed robbery, serious assaults and drug offences. The investigation into the murder of James Nolan remains active, according to sources. He was set free on November 22, 2010, after serving part of a three-year sentence for a burglary and a check of his phone records showed that it had been inactive since the middle of that week.
Investigators have been working on the basis that Nolan was killed some time that week and his body dismembered.
A post-mortem examination on the arm found on the beach on February 8, 2011, confirmed that it had been severed from the shoulder and the hand cut off.
Nolan, from Fairlawn Road, Finglas, was jailed for 14 years when he was convicted of the rape and false imprisonment of a woman in 1986.