The Australian Federal Police (AFP) and Australian Border Force (ABF) have described the seizure of 540 kilograms of methamphetamine in Sydney as one of the 10 largest drug hauls in the nation's history.

The drugs, with a street value of $324 million, were concealed in 396 plastic containers purporting to be protein power, AFP Commander Chris Sheehan said.

Police arrested seven men, in their 20s and 30s, who they allege arrived to pick up the shipment. They have been charged with drug importation and have not been granted bail.

A 23-year-old Green Valley woman also faced Sydney's Central Local Court charged with possession and trafficking drugs.

The men arrested during the 540-kilogram drug bust. ( Supplied: Australian Border Police and AFP )

The AFP said officers carried out a "controlled operation" which followed the substitution of the drug and the delivery of sea cargo from the United States to a storage facility in Smithfield in Sydney's west.

Commander Sheehan said this was the largest haul in 2017, with a total of 5 tonnes of methamphetamines and precursors to the drug seized in the past six months.

Searches were made of several other properties in Sydney's west and south-west, where weapons including an SKS assault rifle, two semi-automatic handguns, a large amount of ammunition, two revolvers, a handgun similar to what the police use, cocaine, MDMA tablets and cash were seized.

"The commercial scale of drug trafficking of this type comes hand in glove with the potential for violence, as evidenced by the seizure of firearms," Commander Sheehan said.

ABF Regional Commander Tim Fitzgerald said an intelligence operation began in May last year after workers at the International Mail Centre in Clyde detected 4kg of cocaine in 17 bottles of vitamins.