Australian authorities have uncovered what is being described as the country’s largest cocaine seizure, with an estimated street value of more than AU$800 million, following a major operation targeting organised crime networks along the east coast.

The discovery was made on a semi-rural property in Londonderry, north-west of Sydney, where Australian Federal Police (AFP) officers allegedly found 2.7 tonnes of cocaine concealed in underground bunkers beneath shipping containers.

Investigators said the drugs were hidden in plastic tubs under false container flooring, in a sophisticated attempt to avoid detection.

The haul is believed to represent around three million individual street-level transactions and ranks as Australia’s biggest cocaine seizure on record.

Two men, aged 21 and 25, were arrested after allegedly attempting to flee when officers executed a search warrant on Friday.

Both have been charged with possessing a commercial quantity of a prohibited drug, an offence that carries a maximum penalty of life imprisonment.

The pair were denied bail and are scheduled to reappear before Penrith Local Court on 13 August.

The seizure forms part of Operation Minjiang, a multi-agency taskforce established in Queensland to combat large-scale drug trafficking.

Since its launch in May, the operation has resulted in the seizure of more than three tonnes of illicit drugs, including cocaine and methamphetamine.

Police allege the cocaine was brought into Australian waters near Midge Point in north Queensland before being transported south under the direction of a Sydney-based organised crime syndicate.

Investigators are also examining the alleged involvement of the vessel MV Wealth, which has been detained in Solomon Islands.

Authorities believe the ship may have played a role in importing the drugs, although the exact origin of the shipment remains under investigation.

Queensland Police Acting Chief Superintendent Troy Pukallus praised the coordinated efforts of law enforcement agencies, saying a local police response in Mackay had developed into a complex investigation targeting a major criminal network operating across multiple jurisdictions