The first to fall was Iacomino Tomasso, formerly the right hand man of legendary Cosa Nostra leader Bernardo Provenzano, also known as "The Capo of Capos," who was arrested in 2006. Tomasso was arrested in Bogota, from where he had allegedly been running a trafficking network that sent cocaine shipments from the Caribbean coast to another Italian mafia group, la Camorra.

According to the authorities, Tomasso worked closely with a Colombian partner, Juan Carlos Davila Bonilla, alias "El Gordo," who was arrested shortly after. The pair also employed the narco-paramilitary group the Urabeños to provide security for their shipments, according to the authoritites.

Two months later, Tomasso's arrest was followed by the capture of two drug traffickers working for rival organization the 'Ndrangheta: Santo Scipione and Domenico Trimboli. Scipione, who is believed to have lived in Colombia since 2000, is one of the highest ranking 'Ndrangheta capos, while Trimboli, working on Scipione's orders, handled the logistics of the mafia's Colombia-Italy cocaine connection.

Officials say that while the 'Ndrangheta also maintained logistical networks in the Caribbean, their main trafficking method was sending shipments from the Pacific coast on boats which head up to the Panama Canal before crossing the Atlantic.

The arrests were the result of a three-year international operation that brought together Interpol with law enforcement agencies from Colombia, Italy, and the US.

InSight Crime Analysis

Iacomino Tomasso has a long history of operating in Colombia and over the years has been a key player in developing networks linking Colombian cartels to the Italian mafia. His capture this year was the second time he has been arrested in Colombia – the first came just weeks after his boss Provenzano was arrested in 2006.

At the time, Tomasso was operating as the Sicilian mafias' point man in the Colombian cocaine trade, making deals and alliances with the drug trafficking organizations in Valle de Cauca, Antioquia, and along the coast.

However, it is the arrests of the Scipione and Trimboli that are key to understanding the main connections between Colombia and Italy today. Over the last 20 years, the 'Ndrangheta has come to dominate the cocaine trade in Italy, and has used its profits -- estimated to be between  $30 and $50 billion a year -- to become arguably Italy's most powerful organized crime group.

The 'Ndrangheta or Calabrian Mafia is one of four main Italian organized crime groups operating today, along with the Cosa Nostra, or the Sicilian Mafia; the Camorra or Neapolitan Mafia; and the Sacra Corona Unita or United Sacred Crown. According to the FBI, the four groups have approximately 25,000 members in total, with 250,000 affiliates worldwide and cells in Canada, South America, Australia, and parts of Europe

The origins of the 'Ndrangheta date back to the 19th century, but the group remained a mostly local federation of crime families until its entrance into the drug trade. According to experts on the 'Ndrangheta, the families first entered the cocaine trade buying imported drugs from the Cosa Nostra, whose entrance into Colombia had been facilitated by Tomasso.

By the end of the 90s, they had established their own networks and worked closely with the notorious paramilitary warlord and leader of the AUC, Salvatore Mancuso, whose appeal was increased by his Italian heritage. By 2004 Italian authorities estimated the group was responsible for bringing in 80 percent of the cocaine that entered the country.

However as the axis of the cocaine trafficking world shifted from Colombia to Mexico, so did the Italian mafia. Again, the Cosa Nostra seems to have led the way, with the brothers Elio and Bruno Gerardi acting as their connection in Mexico after fleeing the attentions of law enforcement agencies in Colombia. But again, the 'Ndrangheta was not far behind: the organization established links with the Gulf Cartel, then did  business with the Zetas after they broke away from the Gulf Cartel in 2010.

However, there are numerous disadvantages for the Italian mafia groups in doing business with the Mexicans. Logistically, it adds an extra leg to the journey, which increases costs and risks. There is also the fact that the big Mexican cartels dominate the cocaine world through wealth, power and violence, which leaves little room for negotiation over who does what and how much they get paid. Then there are the growing signs that the Mexican cartels, among them the Zetas, are looking to increase their influence inside Europe to profit from distribution networks, as they do in the United States.

The fact that the Mexicans are able to force the mafia groups into this secondary role may well be one of the factors fuelling the return of the capos to Colombia. The tectonic shifts in the cocaine trade over the last 20 years have left the Colombian underworld much more fractured and its organized crime groups less capable of asserting dominance. As shown in Tomasso's case, even the most powerful of Colombia's criminal groups, the Urabeños, often do little more than provide traffickers with security services and guard shipments, leaving their cut substantially less than what the Mexicans would take.

It could be, as the Colombian police have suggested, that the rebirth of the Italian mafia in Colombia is little more than Italian traffickers reigniting old contacts after serving prison sentences in Italy. However, given the adaptability and flexibility the groups have shown in the past in finding new markets and opportunities, it is likely also influenced by the fact that they see dealing with Colombians as a way to exert more control –- and thus extract more profits from the cocaine trade.