Investigators discovered 23kg of suspected cocaine on the ship on Monday and it’s expected the search will continue for the rest of Tuesday.

The ship’s crew contacted Port Pirie police to report suspicious packages found within the ship.

Serious and Organised Crime Branch Detective Superintendent Billy Thompson said the amount of cocaine was “very significant” with an estimated street value in excess of $8m.

“If this amount of illicit drugs had successfully entered the drug market it would have no doubt led to significant harm to our community,” he said.

Detectives from Serious and Organised Crime Branch are leading the investigation with the assistance of local police, SAPOL Water Operations, the Australian Border Force and the Australian Federal Police.

Investigators will try to find out the source of the cocaine and how it came to be on-board the ship.

The ship’s crew are assisting police with their inquires.

The bust comes as Australia’s border force struggles to contain the flow of drugs into the country’s ports, as violent drug gangs go to extreme lengths to evade authorities.

In 2022, an alleged cartel diver, Brazilian Bruno Borges, drowned after trying to recover a 50kg haul, valued at $20m, from the bottom of a ship docked in the Port of Newcastle.

Australian Border Force Commissioner Michael Outram has said his team only stops about 20 per cent of drug shipments coming into the country.