'FAT' Freddie Thompson's home was sealed off at the weekend after a suspicious device was found at the property.
Gangland tensions were mounting in the capital after a major security alert at the house, occupied by Thompson's mother, in the south inner city.
The property, in Loreto Road, Dublin 8, was sealed off for two hours yesterday evening after a suspicious device was discovered. It was later declared a hoax.
In the aftermath of the incident, armed gardai continued to patrol the streets around Thompson's home.
Just 24 hours earlier the mobster was spotted in a bar in the Francis Street area. The 30-year-old gangster spent most of the day and night on Saturday drinking in the pub.
He returned to Dublin from Birmingham last week after his family home was firebombed.
The attack, which was caught on a CCTV system installed at the house, could have caused serious injury or death to the occupants of the house.
Instead the petrol bomb caused scorch damage to a door on the property.
The incident led to a furious Thompson returning home and it is understood that he has vowed to defend the property.
Days after the attack the Herald photographed Thompson defiantly standing at the door of the house.
Soon after his arrival in Dublin, Thompson made contact with a number of senior gardai and asked for more protection at his family home.
"He is extremely worried for the safety of his mother and sister. But the truth is that he should have thought about these issues long before he started being so heavily involved in crime," said a source.
It is understood that Thompson has told officers that he is "back for good" after spending almost two years abroad based between Birmingham, Amsterdam and Spain.
Gardai are particularly concerned about a simmering feud between Thompson and a 24-year-old Dublin criminal now hiding in Co Laois.
The rival criminal was present in an incident in which Thompson's brother suffered a broken leg and his wife was stabbed in the face in a south city pub in March.