Australian law enforcement agencies have seized methylamphetamine worth A$1.26 billion ($1.35 billion) in the country's largest-ever haul of the illicit drug in its liquid form, officials said.
Four Hong Kong passport holders were arrested in Sydney last month over the import from China of 720 litres of the drug hidden in boxes of silicon bra inserts and art supplies, police said.
The liquid could have made about 500kg of high-grade crystal meth or P, commonly known in Australia as ice, Australian Federal Police Commander Chris Sheehan said.
Officials also seized 2kg of the crystalized form of the drug.
Justice Minister Michael Keenan said the operation used information gathered through new cooperation between Australian Federal Police and China's National Narcotics Control Commission.
The Australian and Chinese agencies established a joint task force in November to investigate criminal syndicates trafficking methamphetamine.
The four will appear in a Sydney court next month charged with importing and manufacturing commercial quantities of illegal drugs. Each suspect faces a potential life sentence if convicted.
Keenan said the seizure was one the largest hauls of illicit drugs in Australian history.