Potential witnesses in an upcoming trial involving a junior associate of the Kinahan cartel have been warned that they will "get a bullet in the head" if they testify against the young criminal.
Gardai are aware of the "constant threats" which have been issued in a number of south inner city pubs over the past number of weeks.
Gardai from Kevin Street and Kilmainham Garda Stations are investigating the sinister death threats but so far no-one has made an official statement against the Kinahan-linked gangsters who have stepped up their campaign of terror.
The south inner city is their stronghold and many of the outfit's senior members are from the area. The young male, who is facing trial for a serious offence, is not suspected of issuing the threats and he is the subject of careful garda monitoring and strict bail conditions.
"This is a very serious and sinister situation, but thankfully the criminals involved in this behaviour do not know the identity of who has given statements to gardai," a senior source told the Herald.
"Of course when this matter comes before the courts, there will be even more tension when these people testify in a public forum. The level of intimidation surrounding this case has been quite frankly staggering," the source added.
The last major incident involving Kinahan gang members in the south inner city as part of their bitter feud with the Hutch gang is their suspected involvement in the murder of drug dealer David 'Daithi' Douglas on Friday evening. Tensions in the area remain high with regular armed garda checkpoints over the weekend.
The murder of Douglas is not connected to the pub threats or the offence with which the young Kinahan cartel member is charged.
"Even before Friday's murder, things were festering away all the time. These individuals are always plotting against each other but the garda presence had put them off for a few weeks. A lot of these fellas were keeping their heads down, but now gardai are investigating yet another broad daylight murder in the city," the source explained.
Armed gardai continue to monitor the feud which has now claimed eight victims after Friday's shocking gun murder.
It is understood that one of the major flashpoints is the Crumlin area of the capital, where it is feared that criminals aligned to the Hutch faction will carry out an attack on criminal Liam Byrne and his associates.
Liam (35) is the older brother of David Byrne (33) who was gunned down at the Regency Hotel after gunmen dressed in fake garda uniforms stormed the Dublin premises on February 5.
Gardai believe "it is only a matter of time" before the north inner city mob who are feuding with the cartel strike back after seven of the eight murders were carried out by their bitter rivals - six this year alone.
"The obvious concern is that they could go for a spectacular attack again like what happened at the Regency Hotel," a source said last night.
"There has always been the fear of a pub bomb attack in a south inner city pub as well."
Meanwhile it also emerged that a Monaghan man who is a close associate of Gerry 'The Monk' Hutch was released without charge last week after his arrest on Monday over the Regency Hotel attack.
It is understood he was questioned about providing back-up for the assassination team.