Notorious for persuading property owners to hand over cash for tarmacking botch-jobs, the Irish and UK gangs work all over Europe and beyond.
Sunday World has previously revealed how some crews have generated as much as €100,000 in a single week.
In Casciago, north of Milan, last month, police stopped one tarmac crew after receiving complaints about the quality of work being done and the agreed price going up by four times the original amount.
Local media reported that the tarmackers were Irish and Romanian, and a few individuals tried to evade investigating officers.
They were taken to a police station for questioning and their equipment, which had been blocking access to a business, was moved out of the way.
They were later released along with their equipment after it was agreed the property owner pay the amount initially agreed for the work.
Just weeks earlier, in the nearby Renate area, two brothers aged 17 and 24 described as being Irish and driving an English-registered Mercedes were stopped by police.
Officers were alerted after the two young men had approached businesspeople in the area with offers to provide cut-price tarmac.
They were arrested by the Carabinieri and taken to a barracks to establish their identities and to check if any illegal acts had taken place.
Last week, French gendarmes in the Indre et Loire department, near the city of Tours, also posted warnings about bogus tarmackers operating in the region.
Describing them as "specialist fraud gangs" they warned the owners of commercial properties could be targeted by the group and that the "seductive offer is a scam".
They advised anyone engaging people for that kind of work to look for proper documentation and set an agreed price.
They urged people to call police if there was any doubt.
French authorities have previously taken a hard line against Irish gangs engaging in tarmac scams in their country. A court in Limoges issued arrest warrants for three Irishmen last July after they were convicted for their roles in a €280,000 tarmacking scam.
The warrants were issued after the men were given sentences from two years to 12 months in prison in their absence.
The public prosecutor said in court that the crew generated €280,000 worth of business in the period for which they were investigated.
Last November another Irish tarmacking crew were stopped by Spanish police after complaints from local residents, and one man was arrested.
The group of ten were travelling in two cars and an Irish registered truck.