More than $1 billion worth of ice has been found hidden inside stereo speakers in Melbourne in the largest ever seizure of the drug in Australia, authorities say.

Key points: The drugs had been shipped from Thailand to Melbourne

The drugs had been shipped from Thailand to Melbourne Police said they would have supplied almost 16 million drug deals

Police said they would have supplied almost 16 million drug deals Packages of heroin worth $18.5 million were also seized

Australian Border Force (ABF) officials found almost 1.6 tonnes of the drug in a sea cargo consignment that arrived in Melbourne from Bangkok.

"An x-ray revealed anomalies within the speakers and when they were deconstructed, ABF officers found vacuum-sealed packages containing the drugs," an Australian Federal Police (AFP) statement said.

The AFP said no arrests had been made over the ice seizure, which it said had a street value of around $1.2 billion and represented almost 16 million drug deals.

The drug haul is estimated to have a street value of around $1.2 billion. ( Supplied: Australian Federal Police )

Thirty-seven kilograms of heroin, worth $18.5 million, was also found, the AFP said.

The ABF's regional commander for Victoria, Craig Palmer, said the seizure would have a significant impact on drug supply in the state.

"Without the sophisticated targeting and detection capabilities of the ABF, these drugs would have made it to the streets of Melbourne and beyond," Commander Palmer said.

Officials found almost 1.6 tonnes of the drug in a sea cargo consignment that arrived in Melbourne. ( Supplied: Australian Federal Police )

"This is the largest meth bust we've ever seen in this country and demonstrates not only the brazen nature of those involved in this criminal activity but the resolve of the ABF in Victoria and around the country to stop these imports."

In 2017, police charged eight men after seizing 1.2 tonnes of methamphetamine from a boat at Geraldton, on the coast of Western Australia.