Rome: Almost 2 tonnes of cocaine with a market value of more than 400 million euros ($440 million) were found floating at sea off eastern Sicily, in what Italy's tax and customs police on Monday called a record seizure.

The drugs were stored in about 70 waterproof packages, carefully sealed, held together by fishermen's nets and equipped with a luminous signalling device, the Guardia di Finanza said in a statement.

The "peculiar packaging methods and the presence of a luminous device to allow tracking" suggest the haul was dumped at sea by a cargo ship in order for it to be recovered later, the statement added.

Cocaine seizures increased more than five-fold from 3.6 tonnes in 2018, police noted at the time, describing Italy as a key transit route for the cocaine trade, and where Balkan criminal gangs were consolidating their positions.

"Congratulations to the Guardia di Finanza for this extraordinary operation: (I am) against all drugs and for life, no matter what", Deputy Prime Minister and Infrastructure Minister Matteo Salvini tweeted on Monday.