An international hitman arrested in Dublin was in Ireland to kill a notorious henchman for the Hutch gang.
The 58-year-old Estonian, who is wanted in Europe in connection with a number of murders, was found in possession of detailed information tracing the movements and address of the gangster.
The target is a major criminal suspected of being one of the three hitmen who were disguised as gardai in the Regency Hotel murder of rival mobster David Byrne in February last year.
He once infamously warned that the feud would not end until cartel boss Daniel Kinahan was dead.
The Herald can also reveal that yesterday's arrest marks the 11th time that gardai have saved the life of the Hutch criminal, one of the key players in the feud that kicked-off after the cartel murdered his close pal Gary Hutch on the Costa del Sol in September 2015.
The Estonian was arrested yesterday morning at a house in Blakestown, north-west Dublin, and was last night being held on suspicion of conspiracy to carry out murder.
Nicknamed The Butcher, he was arrested, along with two members of the cartel, following a raid on a property identified as being linked to the Kinahans.
One of the arrested men, a 57-year-old, is considered to be a senior member in the cartel.
He was busted a number of years ago with a huge haul of cannabis herb.
He is also a director of a company with another senior cartel member.
It is understood the Estonian hitman had been in the country for 48 hours or less and gardai had been aware of his presence.
He is a former special forces soldier from the Soviet era.
It is thought he moved to the Costa del Sol in the 1990s and took up with the cartel in later years.
He could have banked up to €100,000 for taking out the Hutch target. He was hired after the cartel grew tired of botched murder attempts carried out by lower-level criminals.
"The cartel were sick and tired of junkies botching shooting jobs for them, sometimes killing innocent men, so they hired an individual who is considered one of Europe's most dangerous hitmen," a source told the Herald.
International police forces and Interpol have been in touch with gardai and are on their way to Ireland with the hope of speaking to the man in relation to a number of murders in continental Europe.
It is understood he was caught with information on the Hutch hitman, and one other member of the inner-city gang.
The information on the high- level criminal was of a very detailed nature in relation to his movements and habits.
"This man had written details of Hutch associates and specific information about their movements. He also had a number of disguises," said a senior source.
"This man is infamous and it is suspected he was hired by the Kinahan cartel. He is a war veteran."
Two Irishmen were arrested as part of yesterday's operation and cocaine worth around €5,000 was also recovered.
One of the Irishmen - the 57-year-old - was also last night being questioned on suspicion of conspiracy to murder.
He and the Estonian can be held for up to seven days.
The younger man, aged in his 30s, was being held on suspicion of possession of drugs.
Both were being held under anti-gangland legislation.
Members of the Drugs and Organised Crime Bureau supported by the Special Crime Task Force carried out the raid in west Dublin at around 11am yesterday.
The men were being held at stations in west Dublin last night.
Gardai had not located a weapon but searches were said to be continuing.
The high-level Hutch target of the hitman appeared in court in recent weeks in relation to driving offences and gardai had to place a huge security operation around the Criminal Courts of Justice.
He was previously arrested in the company of Patrick Hutch Jnr, who was later arrested and charged with the murder of Byrne at the Regency.
It is expected he will again be issued with a Garda Information Message (GIM) form informing him that his life is under threat in light of yesterday's development.
The notorious north inner-city criminal is a feared assassin who is suspected of murdering Paul Kavanagh in 2015 and Eamon 'The Don' Dunne in 2010 on behalf of the Kinahan cartel.
However, he severed his ties with the gang after the murder of his close pal Gary Hutch and is now their sworn enemy.
In the aftermath of Gary Hutch's death, sources revealed he refused to attend a number of meetings the cartel tried to organise with him because he was "disgusted and heartbroken" about what had happened to his pal.
Daniel Kinahan, the son of cartel boss Christy Kinahan, was the chief target of the Reg- ency attack but escaped from the hotel unharmed.
"We will not rest until Daniel Kinahan is dead. He caused all of this - it won't end until he's in his grave," the criminal previously warned.
The bloody feud has so far claimed the lives of 11 people, including innocent men Martin O'Rourke and Trevor O'Neill.