A big haul of a rarely seen class A drug detected at Auckland Mail Centre was among five significant drug seizure made by Customs this month.



In Blenheim, Christchurch-based officers arrested a 21-year-old man after mail - bound for Blenheim and containing the rarely seen class A controlled drug dimethylltryphamine (DMT) - was detected at the mail centre in Auckland.



The package contained 18kg of DMT, which was similar to LSD, said a Customs spokeswoman.



Previously small interceptions had been noted in New Zealand, however this was the largest on record.



"DMT is a psychedelic drug where people react very differently to its use depending on the amount consumed and its purity," the spokeswoman said.



"This poses a real risk to health."



A joint operation between Customs and the police led to a search of the property the package was addressed to. Customs officers arrested the man who had been charged with importation of a class A controlled drug.



Customs could not immediately put a street value on the seized drug, because it was not common here and there was nothing to benchmark it against.



Yesterday Customs officers in Wellington arrested a 34-year-old man after they became suspicious of two packages arriving from the United States.



The packages contained 1.2 litres of the class B controlled drug gamma-butyrolactone (GBL), smuggled in nail polish bottles.



The abuse of GBL is widespread throughout New Zealand and is particularly popular in both the night club and party scene as it produces feelings of sedation and euphoria.



The spokeswoman said it was also known as a "date rape" drug because it could render a victim unconscious and produce memory loss. An overdose could cause nausea, vomiting, convulsions, coma, and death.



The man faces two charges of importation of a class B controlled drug, which carry a maximum penalty of 14 years' imprisonment.



On Monday, in a joint Customs and police operation, a 39-year-old man was arrested in Whangarei after Customs officers intercepted a package from the United Kingdom in Auckland.



It contained individually sealed and wrapped packets of the class C drug ephedrine - a substance commonly used to manufacture methamphetamine ('P') - with a total weight of 4kg.



A few days earlier, Customs officers had intercepted another package from Thailand destined for another address in Whangarei containing packets of white powder that were also found to contain 3kg of ephedrine.



Both packages had been declared as herbal powder scrub.



"This amount of precursor could produce between 3.5 and 4.9kg of 'P'," the spokeswoman said.



The man had been charged with importation and possession for supply of a class C controlled drug which carried a maximum penalty of eight years imprisonment



In a repeat of the recent drugs-in-shoes incident, officers in Christchurch caught a man returning from Thailand with pseudoephedrine in his shoes and bag. His companion was carrying more in her luggage. The total weight of pseudoephedrine was 217g.



Both were charged with importation of a class C controlled drug.



"This intercept follows the April incident at Auckland Airport when a group of 10 Malaysian drug couriers, all in the same tour group and all carrying crystal methamphetamine (P) in their shoes, were caught by Customs officers," the spokeswoman said.



At the end of the first quarter of this calendar year, Customs had made 220 interceptions of pseudoephedrine or ephedrine with a potential yield of between 48 and 67kg of methamphetamine removing in the vicinity of $27 million of potential harm from New Zealand, she said.