Dunedin police say the pseudoephedrine seized in a drug bust could have made half a million dollars worth of P.

A 25-year-old man has been charged with importing the drug after police conducted four search warrants yesterday and uncovered 2.2 kilogrammes of the ingredient.

Police say it was probably intended for a destination outside of Dunedin, and it is unusual to find such large quantities of the drug in the city.

It had been imported from China and derived from the Chinese cold and flu medication known as Contac NT.