Irish police said they are keeping an open mind after dissident republican terrorists claimed they murdered a gangster at a Dublin hotel during a weigh-in for a boxing match.
The Continuity IRA claimed responsibility for gunning down David Byrne, 33, from Crumlin in the Irish capital, and wounding two others at the Regency Hotel on Friday afternoon.
The splinter group said it had been retraining and re-arming in recent years and that it sent a six strong gang - three armed with Kalashnikov assault rifles and dressed in Swat team uniforms and helmets - to target the criminal.
It claimed Byrne was singled out in retaliation for the killing of Alan Ryan in Dublin in September 2012 - a leader of a faction of the Real IRA in north Dublin.
"This will not be an isolated incident. CIRA units have been authorised to carry out further operations. More drug dealers and criminals will be targeted. CIRA will carry out further military operations," the dissidents claimed.
In a statement the Garda press office said: "Gardai are aware of the recent statement to the media and are keeping an open mind in relation to the criminal groups involved as part of their investigations."
Senior gardai had ruled terrorism out in the aftermath of the attack and while the claim for responsibility followed a path well worn by terrorists of contacting a respected journalist and the BBC in Belfast with a code word it is difficult to verify it.
Detectives are running a number of lines of inquiries including that the discriminate attack, which targeted Byrne and two others who remain in hospital, was an escalation of a dispute between drugs gangs based in Dublin and the Costa del Sol.
There is further speculation that the gunmen were guns for hire to avenge the murder of Gary Hutch in Marbella last year or if the claim is deliberate misinformation by gangsters or if dissidents are so heavily embroiled in the drugs trade that they have taken sides in a dispute.
Despite the confusion the Continuity IRA is one of a number of dissident groups which makes vast sums of money extorting vast sums of money from major drug dealers in the Republic.
About 300 people were in the hotel when the gang struck, including families with children, boxing fans and a small number of journalists and photographers.
They were attending a weigh-in for a title fight billed Clash Of The Clans between Jamie Kavanagh and Antonio Jao Bento which was due to be broadcast by Boxnation and was subsequently cancelled.
The bout was being promoted by Frank Warren and MGM Promotions based in Marbella.
In the immediate aftermath Byrne's murder was reportedly linked to a gangland feud between major organised crime outfits in Dublin and the south of Spain with speculation that it was retaliation for the murder of 34-year-old Hutch at the Angel de Miraflores apartment complex, in September last year.
There were also reports that Daniel Kinahan, who manages some boxers in the MGM camp, was in the Regency at the time of the attack.
He is the son of Christy Kinahan who was arrested in a mansion in Spain in 2010 as part of an investigation into an international drugs and money laundering racket. He has not been charged.
Some journalists and photographers from Irish newspapers were in the grounds of the hotel anticipating figures from Dublin's criminal underworld would be present.
Amateur video footage of the weigh-in was posted online showing the horror unfold.
Byrne's body was seen by a number of people slumped against the reception desk "riddled" with bullets while witnesses described seeing two other gunmen carrying handguns, one dressed as a woman with an auburn wig and the other wearing a beige flat cap and tracksuit.
Photographs of the gang have been published but gardai requested that media pixellate the faces of two of those not in the Swat style uniforms.
Units of the Garda's armed Emergency Response Unit were sent on patrol in certain parts of Dublin over the weekend with a number of high profile checkpoints set up in the wake of the murder.
No arrests have been made.
And in the heat of a general election in the Irish Republic Justice Minister Frances Fitzgerald came under pressure to explain why journalists took the initiative to stake out the hotel for underworld figures but garda detectives were not there.
"The answer the Garda Commissioner (Noirin O'Sullivan) has given ... there was no operational intelligence in relation to this event," she said, insisting it was not a resource issue.
James McGettigan, managing director of the Regency, also revealed it took three 999 calls before he got an answer, only to be diverted to a second office.
Taoiseach Enda Kenny called on Sinn Fein president Gerry Adams to make a statement on reports that the assault rifles used in the attack may have been from "cargo that came in from abroad with the Provisional IRA a number of years ago".
Mr Adams said: "I understand a group calling itself the Continuity IRA has claimed responsibility for the attack at the Regency Hotel.
"They are not the IRA. The IRA are gone and their weapons are gone.
"Enda Kenny knows that.
"Incidentally, the same group has me and other Sinn Fein reps under active death threat. This was confirmed to me by the PSNI in recent months."