Drinkers of wine, sherry and port may be unknowingly breaking the law and consuming small doses of the party drug fantasy, an illegal class B drug.
The revelation has brought calls for wine to be tested for traces of gamma-hydroxybutyric acid (GHB), or its precursor gamma-butyrolactone (GBL), the active ingredient in fantasy.
Concerns have also been raised about beauty products containing GHB, which have been sold here for years.
The Ministry of Health has just been made aware of the issue and is working on how to deal with it.
National Addiction Centre director Doug Sellman said it seemed likely some wine contained GHB, and called for more research to be undertaken.
"It raises the bizarre conclusion that many wines in New Zealand may, in fact, be technically illegal. There's been no research done on New Zealand wines, and only one article in 2005 in the international literature."
The paper found GHB or GBL occurred naturally in fermenting grapes. It looked at 50 beverages in Britain and found the ingredient in red-wine vermouth, sherry, port, red wine and white wine.
The concentration of GHB ranged from 4.1mg to 21.4 mg per litre, the greatest concentration being found in red wine. Doses as a recreational drug are usually between 500mg and 3000mg.
Dr Sellman said he was not calling for prohibition, but wine-drinkers were essentially using fantasy in small but significant amounts.
"We're not talking about trace amounts. If you drank a bottle of wine, a small but significant part of that intoxication will be from fantasy."
But Environmental Science Research general manager of forensics Dr Keith Bedford said the level of GHB in wine was virtually meaningless.
"You can consider the effects as being very similar to alcohol. Compared to the amount of alcohol in alcoholic drinks, what we're talking about is trivial."
Associate Health Minister Peter Dunne said "there'd be a measure of outrage" if wine were found to be illegal.
"A fair measure of common sense would need to be applied."
