Almost $80 million worth of MDMA hidden in an excavator and shipped from Britain to Australia was sent to an auction house and purchased by a knowing drugs importer, according to federal police.

Just under 450 kilograms of the party drug – which police allege has a street value of $79 million – was found in March, inside the excavator that arrived in Brisbane from Southampton, on Britain’s south coast.

Federal police allege the machine was then consigned to a Sydney auction house and bought by a man who knew of its illicit contents – some 226 plastic bags of MDMA.

Almost 450 kilograms of MDMA was found inside the excavator.

The AFP said it detected the “suspect shipment of an excavator” on its way to Australia.

“AFP Forensics officers did some digging and removed 226 plastic bags containing a crystalline substance hidden within the arm of the excavator,” it said.

Border force officers had the excavator X-rayed when it arrived in Brisbane – revealing “anomalies” inside the arm of the machine.

A 33-year-old Mortlake man and a 42-year-old Greystanes man have both been charged with attempting to possess commercial quantities of border controlled drugs.

The offence carries a maximum penalty of life imprisonment.

AFP Assistant Commissioner Justine Gough said more arrests might follow.

“The group thought hiding drugs in machinery and consigning it to a legitimate auction house would be an innocuous way to avoid detection in Australia, and indeed, they were very wrong,” Ms Gough said.

“Drug use has a devastating impact on individuals and Australian families.”

Another three men – aged 53, 60 and 57 – were arrested by authorities in Britain and charged with conspiring to export illicit drugs.

They are accused of sourcing, concealing and exporting the drugs, as well as arranging for one of the Australians to purchase the excavator.

-with AAP