Two customs brokers and another man have been charged over a mammoth methamphetamine haul with a street value of more than $1 billion hidden in stereo speakers in Melbourne.
The 1.6-tonne haul - equal to almost 16 million drug deals - is the largest ever onshore seizure of the drug and was uncovered earlier this year, according to Australian Federal Police.
"It's almost a quarter of the annual usage in Australia, so this will have an impact," AFP Deputy Commissioner Neil Gaughan told reporters on Thursday.
The charges follow raids on properties in Brooklyn, Darley, Elwood, Murrumbeena and Sunshine West on Wednesday.
Mr Gaughan said two of the people charged - a man and a woman - were customs brokers involved in the transport of goods between facilities.
They do not have security clearance, but operate as independent import-export experts who know how the system works.
"They are trusted insiders in the industry. They used their position of trust to circumvent the border controls that exist within Australia," he told reporters.
"This vulnerability has been fully removed."
They were not federal or state government employees, he added. Rather, the duo were likely used by an organised crime syndicate.
"There's people above them, we think we know who they are, we'll keep working on the investigation to try to bring them to justice as well," Mr Gaughan said.
The haul was found by Australian Border Force officers in Melbourne in April inside a sea cargo consignment concealed in stereo speakers.
More than 35kg of heroin, with a street value of $18.5 million, was also discovered. It's the largest seizure of heroin in two years.
ABF Assistant Commissioner Sharon Huey said officers were alert to "all types of creative and sophisticated methodologies" used by organised crime syndicates.
"Our officers have really seen it all. We've seen drugs in highlighter pens, hot sauce and even cowhides. Nothing surprises us," she said.
The consignment came from Thailand, but authorities believe it originated from another southeast Asian country.
An investigation by authorities in Thailand continues
Two men, aged 37 and 38, and a 37-year-old woman, will face Melbourne Magistrates Court on Thursday on drug importation charges.
The maximum penalty for a conviction is life imprisonment.
Australian Associated Press