The Australian Federal Police says cocaine seized is testing positive to levamisole - an animal worming agent that can induce skin infections in humans - as well as phenacetin which was withdrawn in Canada and the United States decades ago due to causing cancer and kidney damage.

It is estimated Australians consume about 5.6 tonnes of cocaine each year and police are urging caution after their latest find.

"Drugs are often cut to a low purity using a range of potent chemicals and fillers,'" AFP Commander Forensic Operations Paula Hudson said.

"We are imploring Australians to be safe this Christmas and be mindful that their lives are often in the hands of brutal cartels and transnational serious organised criminals, like outlaw motorcycle gangs in Australia, who do not care about what toxic substances are being mixed with illicit drugs, which are dangerous in their own right."

Cocaine consumption has grown in Australia by more than 80 per cent over the past five years and prices are among the highest in the world, boosting the bottom line of criminal syndicates.

But not all of the illegal shipments are slipping past police.

The AFP has made several major cocaine busts in recent times, seizing 1.12 tonnes of the drug with its partners this year including 590kg in a single haul this January.

Australian Associated Press