The seizure of 4.3 tonnes of cocaine came at the end of an international investigation that resulted in arrest warrants being issued for 38 people in six countries.

Besides the cocaine, police also confiscated 1.85 million euros in cash.
Besides the cocaine, police also confiscated 1.85 million euros in cash. (AP)

Italian police have seized 4.3 tonnes of cocaine with a street value of $257 million, dealing a heavy blow to the Colombian Clan del Golfo drugs gang, investigators have said.

Police said on Tuesday that it was one of the largest such seizures in Europe and came at the end of an international investigation that resulted in arrest warrants being issued for 38 people in six countries: Italy, Slovenia, Croatia, Bulgaria, the Netherlands and Colombia.

The investigation lasted more than a year and involved both the Colombian judiciary and US Homeland Security. 

Besides the cocaine, police also confiscated 1.85 million euros in cash.

Colombian authorities said last November they were focused on breaking up the Clan del Golfo gang, whose network extends to 28 countries around the world, after the capture of the group's leader, Dairo Antonio Usuga, alias "Otoniel", in October.

READ MORE: Colombia extradites 'world's most wanted' drug trafficker to US

'Dense network'

"Another hard blow to the most important group among Colombian narcotics gangs," Italian investigators from the northeastern city of Trieste said of the seizure.

They said their work had uncovered a "dense network" of ties between South American cocaine producers and European buyers, who answered to organised crime groups operating across Italy, including in Calabria, home of the 'Ndrangheta mafia.

They said police had followed 19 consecutive deliveries of drugs from May last year, enabling them to identify "important middlemen" in the global drug trafficking system and a "substantial number" of carriers.

READ MORE: Who are the 'Ndrangheta? Italy's most powerful crime syndicate

Source: Reuters