The notorious Christy Kinahan cartel are closely associated with a feared mob who are involved in a deadly criminal feud being played out in Amsterdam.
The Dutch violence has proven to be more deadly than the Kinahan cartel's bitter gang war here with the Hutch mob.
The feud in the Netherlands has already led to:
It emerged this week that the Irish cartel have been closely linked to a vicious Dutch mobster, Gwenette Martha, who was shot dead in central Amsterdam in May 2014 - three months after two hitmen gunned down fellow gang member Mohammed el Mayouri near a cafe.
"The links between these crime organisations is being actively investigated by police forces across Europe and has been for some time," a source said last night.
"It is well known that many of the key players in the cartel, including Freddie Thompson and Christy Kinahan Snr, have spent time living in Amsterdam.
"It is not believed that they have been active participants in the Netherlands feud - but investigations have established they are strongly linked to one side that has been involved in the bloodbath there and have been for a number of years," the source explained.
"It has been established that there have been meetings between players in the Dutch gang and the Kinahan cartel in Ireland, Holland and Spain.
"In turn, a number of English gangs are also associated with this crime network," the source added.
The latest gruesome incident linked to the Dutch feud occurred on March 9 when a severed head was found outside a shisha cafe in Amsterdam. The victim's decapitated body was found the previous day.
The head was discovered outside the Fayrouz lounge close to Amsterdam's popular Vondelpark.
It was found inside a blue bucket on the pavement and was "turned so that his face looked through the windows". Detectives identified the body as 23-year-old Nabil Amzieb, and said he was "known to police".
It is understood he was due to give evidence in a trial related to the bloody feud.
The man was part of the city's Moroccan mafia, according to Dutch newspaper, the Telegraaf.
Local media reported the location where the head was found is a significant place for the gangs of the city, who are involved in what the paper calls the "Mocro war".
It is understood an associate of the Kinahan cartel is a suspect for this brutal murder.
The lounge was reported to have been a meeting place for criminal activity since 2012, according to NL Times.
At least 16 people have died in the Netherlands, Belgium and Spain in related underworld killings since March 2012, when a gang stole almost €20m worth of cocaine - most of it reportedly destined for the Irish and British market - entering Europe through the Belgian port of Antwerp.
Another notable murder in the bitter Amsterdam feud was that of Luana Luz Xavier (34), the girlfriend of an Amsterdam criminal involved in the feud, who was shot dead in front of her teenage daughter and son in December 2014.
Six months earlier, innocent custom services manager Stefan Eggermont (30) was shot dead in a case of mistaken identity as part of the feud.
In scenes similar to February's Regency Hotel gun attack in Dublin, Kinahan-aligned mobster Gwenette Martha was shot dead in an Amsterdam suburb as he came out of a kebab shop in March 2014.
Despite wearing a bullet-proof vest, he was hit by 80 rounds from two or more AK47 rifles. So many rounds were fired that Dutch police said it was a miracle no-one else was hit.
The bitter Amsterdam feud has led to several public shootouts that began with the murder of Najeb Bouhbouh (34) who was gunned down at the Crowne Plaza hotel in Antwerp, Belgium in October 2012.
Ironically, cartel overlord Christy Kinahan Snr. was residing in Antwerp at this time but in the city's main jail serving a four-year sentence for fraud-related offences.
The money-laundering case was brought against the drug boss following his arrest by Belgian federal police, in May 2008 who later released him.
He was extradited to Belgium from Spain in 2010 as part of the massive international Operation Shovel into his estimated €500m drugs enterprise before leaving jail in Belgium three years ago.
Meanwhile, sources say that tensions remain high on the streets of Dublin after last week's murder of innocent dad-of-three Martin O'Rourke who gardai believe was shot dead by a Kinahan gun-for-hire whose intended target was Hutch mobster Keith Murtagh (32).
It emerged last night that the cartel are attempting to find out Murtagh's location in the UK in an attempt to murder him.