The suspects are alleged to have demanded payment of 3,000-5,000 euros ($3,100-$5,200) in cash per person, packed the boats with 10 to 30 passengers at a time, and pocketed 30,000-70,000 euros for each four-hour journey, police said in a statement.
The investigation was launched in February 2019 after a fisherman in Sicily's port of Gela noticed a 10-meter glass fiber boat with two 200-horsepower motors. Investigators discovered the boat had been stolen 10 days previously in Catania, Sicily, ABCNews reported.
Arrest warrants were issued for 11 Tunisians and seven Italians. They face charges of illegal cross-border trafficking of more than five people, with the aggravating circumstance of inhuman treatment and endangering the lives of migrants and committing crimes for profit.
A Tunisian couple already jailed on a people-trafficking conviction were identified as the presumed masterminds of the scheme.
Two Tunisians based in Sicily were accused of having managed the money, while five Italians allegedly organized housing for the migrants and transfer of the traffickers to and from ports.
The warrants also target four other alleged traffickers, one Italian and three Tunisians, and four Tunisians who made connections with the migrants in northern Africa.
Also sought is the owner of a small farm with a private airfield that allegedly functioned as a base for the operation. The farmer was accused of providing employment documents for some of the Tunisian operatives to legitimize their presence in Italy.
While the new Italian government has cracked down on humanitarian rescue ships that pick up migrants departing Libya in the central Mediterranean Sea, the majority of migrants arriving in Italy travel along routes from Tunisia.