Authorities have launched an investigation after intercepting more than $430 million worth of the drug ice inside a shipment of refrigerators.

Key points: The container was wrongfully declared as a shipment of electric ovens

The container was wrongfully declared as a shipment of electric ovens Officers found 585 kilograms of methylamphetamine hidden inside the fridges

Officers found 585 kilograms of methylamphetamine hidden inside the fridges Police raided three properties in Sydney on Friday, but no arrests have been made

The container, which was shipped from Singapore, was declared to contain electric ovens.

But when examined by police at Sydney's Container Examination Facility on March 30, officers found 11 commercial refrigerators inside.

X-rays suggested there were inconsistencies with the make-up of the fridges, prompting officers to investigate further.

Upon removing the back panel of seven of the fridges, officers discovered 561 packages of white crystalline substance.

Testing later revealed the substance was methylamphetamine, also known as ice.

Superintendent Garry Low of the Australian Border Force said while they looked like ordinary fridges to the blind eye, police were easily able to discover the drugs inside.

"It was a fairly crude import and disguised in fairly basic manner," he said.

Police discovered the drugs simply by removing the back panels of the fridges. ( Australian Border Force )

Police estimated the drug shipment, weighing 585 kilograms, had a potential street value of $438 million.

"[It's] the largest that's been seized in NSW this year and obviously one of the largest that's ever been seized," Superintendent Low said.

The discovery prompted the establishment of a joint investigation involving the Australian Federal Police, NSW Police Force's Organised Crime Squad, and the Australian Border Force.

On Friday, police conducted raids on three Sydney addresses — two commercial premises at Wetherill Park and a home at Edensor Park.

Officers seized documents and computers during the raids, which are now being examined.

No arrests have been made.

The container was shipped to Australia from Singapore. ( Australian Border Force )

Detective Acting Superintendent Damien Beaufils of the NSW Police Organised Crime Squad said the probe extended to overseas locations, but did not specify where.

"There'd be some people that are out of pocket a lot of money, we're happy to speak to them if they want to come forward," he said.

Police are urging anyone with information in relation to organised criminal activity to contact Crime Stoppers by calling 1800 333 000 or going online to nsw.crimestoppers.com.au.