Kinahan hitmen are in the North actively planning a revenge hit the suspected shooter nicknamed 'Flat Cap' from the Regency Hotel murder.
The dissident republican was pictured leaving the Drumcondra premises armed with a handgun alongside another man dressed in drag.
Gardai are working closely with the PSNI who have been carrying out surveillance on 'Flat Cap'.
Sources have also revealed that investigating gardai are preparing a file for the DPP, which recommends that this man is charged with the murder of David Byrne (33) at the hotel.
Once the DPP returns with a direction, members of the PSNI will arrest the hitman and an extradition warrant will be sought so that he can be prosecuted in the Republic.
However, it has emerged that the Kinahan cartel has sent gang members to the North in a bid to carry out a hit on the individual before he is arrested.
Also pictured fleeing the Regency Hotel in the aftermath of the shooting was a raider dressed in drag, who was armed with a black handgun.
It is believed that this man fired the initial shots during the hotel hit.
Witnesses described how he acted as "a feeble old woman" before producing a firearm.
Senior detectives were last night continuing to question a man aged in his 20s, who they suspect was the gunman dressed in drag.
He is a close associate of slain Gary Hutch (34) and was arrested by members of the Emergency Response Unit (ERU) on Friday night on the Malahide Road.
The elite unit 'hard stopped' a black Nissan Almera being driven by another criminal suspected of being involved in the Regency Hotel hit.
The gun-for-hire, who is aged in his late 20s, was arrested for road traffic offences. However, he was released without charge early yesterday morning.
Gardai investigating the Regency Hotel attack are also expected to make a number of further arrests in the coming weeks.
Sources have revealed that investigators used facial recognition software to formally identify the suspect, who is a close associate of Gary Hutch, whose murder by the Kinahan cartel in Spain last September sparked the current spiral of feud violence.
The same technology also confirmed the identity of the veteran republican hitman wearing the flat cap.
Meanwhile, it has also emerged that a number of other individuals are also likely to be arrested over their roles in helping the killers make their getaways and hide weapons after the attack.
Detectives have also discovered that a well-known veteran crime figure was also centrally involved in the planning of the Regency attack and drove members of the gang away afterwards.
Gardai suspect over a dozen people were directly involved in the shooting and subsequently driving getaway vehicles.
Five gunmen stormed the hotel - three dressed as fake garda ERU members and carrying AK-47s - during the February 5 hit.
Another individual drove a Ford Transit van from the scene, while a number of vehicles, including taxis, were used to collect the hit team from the Charlemont housing estate where the van was burnt out.
Gardai also believe a gang member acted as a spotter for the hit team.
More individuals were involved in other logistic aspects of the hit, including sourcing weapons and moving the firearms before and after the shooting.
The feud's most recent victim, Michael Barr (35), was shot dead after Kinahan associates suspected him of sourcing weapons for the hit.
He became the sixth feud victim, but gardai fear several more hits will be carried out.
Security concerns have also caused the daughter of Gerry 'The Monk' Hutch to postpone her wedding over fears that the event could be targeted by the Kinahan cartel.
The Monk's youngest daughter was due to get married to her DJ fiance in Clontarf next month.
It is now expected to take place outside of Ireland and will be a low-key ceremony.
Gerry Hutch's eldest daughter previously got married in Clontarf in 2006, and the former crime boss briefly posed for pictures with the bride outside the church.
It is understood that The Monk's family - who are not involved in crime - were moved from the leafy Dublin suburb following the outbreak of the current gang feud.