Federal police have seized some 2000 litres of the drug GBL, which was hidden inside containers labelled as car wash shampoo, and was allegedly destined to hit Sydney's streets in time for next month's Mardi Gras parade.
Abedelrahman Masri, 30, was arrested after the drugs - worth up to $10 million - were seized following a tip-off, authorities revealed on Friday.
The GBL was allegedly smuggled into Australia on a ship that had travelled from China to Sydney, the Australian Federal Police and Australian Border Force said during a joint press conference at Port Botany.
The bust is the second largest haul of GBL - often nicknamed "coma in a bottle" - in Australia and the biggest since 2008.
"GBL kills people, it is a corrosive industrial solvent that can be used for stripping paint and a range of other industrial applications," AFP Commander Chris Sheehan told reporters on Friday.
GBL metabolises in the body as the so-called "party drug" GHB and has been known to induce seizures and rapid unconsciousness.
Sexual predators have used GHB and synthetic derivatives like GBL - which appears odourless and colourless - to spike drinks and commit sexual assaults.
Border force officers received information in early February that a high-risk shipping container would be arriving in Sydney.
Afer examining a shipment of 120 barrels, each containing 200 litres, 10 of the barrels returned a positive result for GBL.
"Our assessment is that this shipment was most likely an opportunistic one and destined to target the anticipated surge and demand associated with the upcoming Mardi Gras here in Sydney," Mr Sheehan said.
Masri, from Warwick Farm, was charged with one count of importing a commercial quantity of a border control drug. It carries a penalty of up to life imprisonment.
He made no application for bail and it was formally refused when he appeared in a Sydney court on Friday afternoon.
Australian Associated Press