Eight men have been charged after a record 1.2 tonnes of methamphetamine were brought in by boat to the port of Geraldton in Western Australia.

Key points: A record Australian meth haul — 1.2 tonnes with a street value of $1.04 billion

A record Australian meth haul — 1.2 tonnes with a street value of $1.04 billion Boat intercepted by police after arriving at Geraldton marina, eight men charged

Boat intercepted by police after arriving at Geraldton marina, eight men charged Vessel was transporting drugs destined for east coast from a Chinese "mother ship"

Police estimate the drugs seized in the operation have a street value of $1.04 billion.

It is the largest meth bust in Australian history, topping a 903-kilogram seizure in Melbourne earlier this year.

Based on the National Wastewater Drug Monitoring results released last week, the haul would have been enough to feed the meth appetite of the entire country for two months.

The 1.2 tonnes is also larger than the total amount of meth used in the city of Perth in a year.

Australian Federal Police display a haul of 1.2 tonnes of methamphetamine, worth more than $1 billion, seized in Geraldton. ( ABC News: Nicolas Perpitch )

Vessel was a link to drug 'mother ship'

The Australian Federal Police and its WA Joint Organised Crime Task Force were monitoring the boat, Valkoista, when it arrived at the port of Geraldton, 400 kilometres north of Perth, at about 2:00am on Thursday.

Officers have removed a number of packages from the boat after it was escorted into the Geraldton marina. ( ABC News: Jessica Hayes )

Police allege the drugs were then offloaded into a white hire van shortly before 4:00am. Tactical response police officers intercepted the van as it reversed from the dock.

Three men in the van were arrested at the time. Police then boarded the boat and arrested three crew members on board.

Police allege 59 bags each containing about 20 kilograms of methamphetamine — commonly known as "ice" — were seized from the van. Another 20kg bag was also allegedly found on board the boat.

A van intercepted by Australian Federal Police officers in Geraldton contained a record 1.2 tonnes of methamphetamine. ( Supplied: AFP )

Police believe the drugs originated in China, but this shipment was picked up from a "mother ship" off the WA coast to transport to the mainland.

Police would not reveal the location of the suspected "mother ship," but said it was being monitored as part of an ongoing international police operation.

Onlookers on Thursday witnessed officers removing a number of sealed packages from the vessel at the Geraldton marina.

How did 1.2 tonnes of drugs get to Australia? Law enforcement agencies believe the methamphetamine was manufactured in China.

Law enforcement agencies believe the methamphetamine was manufactured in China. The drugs were loaded onto a "mother ship" which sailed to a position off the WA coast.

The drugs were loaded onto a "mother ship" which sailed to a position off the WA coast. 60 bags, each weighing 20 kilograms, were allegedly transferred from the mother ship to the marine vessel Valkoista.

60 bags, each weighing 20 kilograms, were allegedly transferred from the mother ship to the marine vessel Valkoista. The Valkoista allegedly sailed to the port of Geraldton, 400km north of Perth, to offload the drugs.

The Valkoista allegedly sailed to the port of Geraldton, 400km north of Perth, to offload the drugs. The drug-filled bags were allegedly loaded into a white van waiting on the dock, where they were seized by police.

The drug-filled bags were allegedly loaded into a white van waiting on the dock, where they were seized by police. Police say the drugs were destined for the eastern seaboard to be sold to the public.

Eight men charged

Six of the men, aged between 33 and 52, were charged with importing commercial quantities of border-controlled drugs suspected of being unlawfully imported.

Patrick Leonardo Bouhamdan and Christos Cafcakis, from South Australia, and Waseem Sliwa Hermiz, Khalid Elia Keana, Serupepeli Anthony Rasaubale and Joshua Joseph Smith, from New South Wales, have each made a brief appearance at the Geraldton Magistrates Court.

Sorry, this video has expired Police confirm Australia's biggest ever meth haul worth over $1b seized off WA coast

Two other men from South Australia were later arrested at a hotel in the northern Perth suburb of Hillarys and charged with importing commercial quantities of border-controlled drugs.

Sean Michael Dolman and Stephen John Baxter, both 37, appeared briefly in the Perth Magistrates Court on Friday morning and were not required to plead to a charge of importing a commercial quantity of a border-controlled drug.

Neither of them applied for bail and they were remanded in custody to appear in court on January 17, when their six co-accused are also next scheduled to appear.

The offences carry a maximum penalty of life imprisonment.

It's the second time in as many years that authorities have intercepted a vessel off the coast of Geraldton with links to drug trafficking.

In May 2016 the trawler Mega Profit II was seized, after a Chinese and Malaysian syndicate used it to drop off 182 kilograms of ice on a stretch of beach 30 kilometres south of Port Denison.

Prosecutors say the Mega Profit II may have been named by "someone with a sense of humour". ( ABC News: Sarah Taillier )

Earlier this month, seven Malaysian and Chinese nationals were found guilty by a Supreme Court jury of charges arising from the importation. Another six men were acquitted.

The convicted men are due to be sentenced next year.

Drugs destined for east coast: police

AFP Deputy Commissioner of Operations, Leanne Close, said police were continuing to gather and evaluate evidence.

"The AFP will allege in court these men intended to distribute the drugs along the east coast of Australia — what these men didn't count on was a calculated, intelligence-led response from the WA Joint Organised Crime Task Force which drew on the strengths and capabilities of the different agencies involved."

Australian Border Force WA Regional Commander Rod O'Donnell praised the work of all involved, including Border Force officers, the AFP and WA Police.

"Australia's maritime border is vast and some criminals clearly think they can exploit that and evade detection - they are wrong.

"These criminals should always assume we are nearby and we are watching."

Home Affairs Minister Peter Dutton praised the efforts of police, intelligence and border force agencies.

"This is a billion-dollar bust," he said

"Particularly at this time of year we're very pleased that [more than] 12 million hits of methamphetamine will be off the streets over the Christmas/New Year period.

"There are kids in Australia who will have their lives saved because of the impact that the police have had in the detection of these drugs."