"More people were reported to be using Ecstasy in 2010 compared to 2009," the report said. "The greatest increase in Ecstasy use was reported in Auckland.
"There was a dramatic increase in the proportion of frequent drug users in Auckland who had purchased Ecstasy weekly or more often in 2010 compared to 2009."
The frequent Ecstasy users were more likely than the other survey participants to be "younger, students, and educated."
Dr Wilkins said yesterday that the increasing production of Ecstasy in Asia might have contributed to the greater availability and lower prices in New Zealand, but there might also be increased demand following the banning of BZP party pills in 2008.
"Maybe BZP party pills created a market of people who were used to using pills in dance-party situations, so when BZP was made illegal, Ecstasy was the next thing around.
"When we banned BZP in 2008 it's likely there might have been a big stock of it left over and maybe that's increasingly being sold as Ecstasy," he said.
"They can get more if they sell any left-over BZP as Ecstasy rather than selling illegal BZP. The price of Ecstasy is higher than BZP ever was."
Laboratory tests have shown seized New Zealand Ecstasy to contain BZP and several drugs similar in effect to Ecstasy.
"People should be aware they may not be getting MDMA [Ecstasy]," Dr Wilkins said.
"They might get a bunch of chemicals that are entirely different and could include methamphetamine."
"Methamphetamine has got a really bad reputation at the moment as quite a harmful drug. One way to sell methamphetamine is to call it Ecstasy and sell it as a powder."
The survey found a reduction in the use of crystal methamphetamine - "ice" - by frequent methamphetamine users.
Dr Wilkins said this might be because of increased border security.
This trend was also reflected in a big decline in methamphetamine use by Ecstasy users, which the report said might be because of methamphetamine's strong association with drug addiction, mental illness and high levels of drug-related harm.
Ecstasy
* New Zealand's second most commonly used illegal drug, after cannabis.
* Class-B drug.
* Produces a sense of energy and alertness, and empathy for others.
* Not highly addictive.
* Lower risk than many illegal drugs, but can be fatal as it can cause extreme overheating.
Source: Massey University and Dr Chris Wilkins