The 295kg illicit drug haul has an estimated street value of $184 million, authorities say.

Police raided four properties around Sydney on Tuesday and three men are facing possible life sentences after being charged over their alleged role in the importation.

Police also seized more than $200,000, encrypted communications devices and kilos of cannabis.

Afif Saliba, 30, is due to face Central Local Court on November 3 charged with attempting to possess a commercial quantity of an unlawfully imported border controlled drug.

His co-accused, Antonio De Luca, 26, is expected to face the same court on December 15, along with Raymond Saab, 25, who has also been charged with importing a commercial quantity of methamphetamine in addition with the attempt to possess charge.

Australian Border Force officers X-rayed the excavator when it arrived in July and detected "anomalies", Superintendent Graeme Campbell said.

Drug detection dogs also showed interest in the shipment and a further examination found metal boxes inside layers of concrete, steel and lead.

"It was a really clever concealment," Supt Campbell said on Thursday.

However, he reminded would-be importers the ABF and its partner agencies "can find these goods no matter how clever and imaginative these criminals are".

The drugs were removed and the excavator was delivered to a Penrith business before being moved to Arndell Park two weeks later, where Mr De Luca and Mr Saliba allegedly spent several days attempting to extract the drugs to no avail.

Australian Federal Police Acting Superintendent Luke Wilson said international groups were targeting Australia because the demand and prices for drugs were so high, with no sign of that changing any time soon.

Australian Associated Press