Police say the number of people trying to buy large amounts of drugs that can be used to make methamphetamine might increase because of a major seizure last week.
Customs announced the finding of 80kg of cold and flu medicine containing pseudoephedrine on Friday.
It was enough to make about $20 million worth of the drug, also known as "P".
Police warn pharmacists to be vigilant in the coming weeks as traders known as "pill shoppers" attempt to make up a shortfall on the black market.
