Acting on intelligence, Australian border police examined sea cargo containers arriving at Port Botany, one of Australia's largest container ports located to the south of Sydney, over the past month.
In two separate cases, police found large amounts of methamphetamine, colloquially referred to as "ice," concealed within blocks of marble stone. Police seized the first consignment containing 748 kilograms (1,649 pounds) of the drug last month, which resulted in arresting and charging three men aged 24, 26 and 34.
The most recent batch of 1,060 kilograms of the drug disguised with the same method was found last week. No charges have been brought against the smugglers involved in this case, but police do not rule out further arrests.
"In total, more than 1800kg of 'ice' – which has an estimated potential street value of more than $1.6 billion – has been detected and seized during this investigation," police said in a statement.
On Monday, Australian Federal Police seized the largest ever shipment of fentanyl, an opioid that can be fatal from a dose equivalent to only two grains of salt.
Methamphetamine is a potent synthetic stimulant drug, sometimes prescribed as a treatment for certain medical conditions, which may cause substantial health adversities and addiction if taken without medical supervision.