The drug was found aboard an âultra-fast ocean-going rigid inflatable boatâ, which smugglers typically use to recover illicit cargoes dropped at sea by large ships arriving from South America, the Guardia di Finanza police said in a statement.

Four people aboard the vessel were arrested - two Spaniards, a Gibraltar resident and an Albanian man living in Italy.

The operation was conducted in cooperation with Spanish and Portuguese authorities, with Italian prosecutors in the northern city of Brescia coordinating investigations.

âThe wholesale value of the cocaine is estimated at approximately â¬78 million. Once delivered to their destination and diluted for retail distribution, the narcotics could have generated total revenues of around â¬500 millionâ, the statement said.

($1 = 0.8772 euros)

(Reporting by Alvise Armellini, editing by Giulia Segreti)