The Government's success in combating drug smuggling will only go so far, as drug dealers find new and innovative ways to get their stuff into the country, customs and drug specialists warned yesterday.

Prime Minister John Key announced that a total of 230kg of the precursor pseudoephedrine - used to make the drug methamphetamine, or P - was seized by customs between October and last month. The figure compares with 67kg of the same substances seized in the same period last year. The amount seized is estimated to produce about $84 million worth of P.

In October the Government announced that a plan on clamping down on the P problem would include boosting numbers of customs staff to monitor and check for drug ingredients at the border. Up to 140 customs staff were involved in the initiative.

Mr Key said the success of the interceptions was evident not just in the amount seized, but also in the anecdotal evidence that the price of P on the streets was getting higher - showing that it was becoming harder to get.

"The fact that we've had such a successful result shows you what a difference it can make when you really focus on something," Mr Key said.

A move to change laws surrounding the over-the-counter availability of the precursor at chemists would also help cut the dealers from supplying methamphetamine, Mr Key said.

Mike Sabin, managing director of drug education group MethCon, said the Government action was positive.

However, efforts to clamp down on people making and using the drug P needed to be strengthened, as foreign dealers and local suppliers would only find other means of producing and selling their product.

"It won't be enough if people still want it," Mr Sabin said. "What the Government strategy lacks is adequate demand reduction - preventing people from using the drug in the first place. Education, marketing and changing social norms - put money into that [because] the smart money is trying to steer people from using."

Fifteen arrests were made as a result of customs interceptions.

Although efforts to stop drugs from getting through customs have increased, customs did acknowledge that the large amount was also due to the fact that they were still getting "masses" of drugs coming in.

New ways to get the drugs past customs were becoming increasingly innovative as it became harder to get in, the spokesman said, with people hiding ingredients in children's toys and blankets.