Each Cheeky plastic pouch contains 25ml of flavoured liquor with a 20 per cent alcohol content and claims to pack "more punch than your average RTD (ready-to-drink)". A rival Sneaky shot contains 21 per cent alcohol and its dedicated Facebook page shows pictures of apparent drunkenness.
The Cheeky website emphasises the convenience of concealing the condom-like sachets in wallets and pockets or "other comfortable crevasse (sic)."
A social media campaign also pushes an "anytime, anywhere" message and says the shot may come in handy "while fishing at sea or a night out on the town".
Cheeky part-owner Lewis Gyde said the product was a new way to carry portion-controlled shots of alcohol.
"It means, if you are going to the beach or on a fishing trip, rather than carrying around a six-pack, you can take one small can of Coke and a couple of sachets to drink."
The sachets were intended to be diluted with mixers, he said.
Police alcohol harm prevention manager Inspector Ben Offner said he was "dismayed, to be honest. We're exploring our options on how we can influence their availability".
He said it was disturbing that the product was clearly directed at young people and encouraging them to circumvent the law.
This week, the Sale and Supply of Alcohol Act 2012 brought sweeping changes to curb New Zealand's drinking culture, including early closing times and fines for serving drunk people. Police are now able to issue $250 spot fines to people breaching alcohol bans.
Brewers Association spokeswoman Jenny Cameron was concerned the sachets could top up drinks in bars, be smuggled into sports venues or used to spike drinks.
"This type of product innovation is precisely the sort that falls foul of the new law and we hope the authorities will act swiftly to exercise their new powers," said Cameron.
Under the new laws, an alcohol product can be banned if it encourages irresponsible consumption or has special appeal to young people.
Cameron said the Cheeky Facebook page and website broke Advertising Standards Authority rules by linking alcohol consumption with the workplace and using models who looked younger than 25.
Dr Andrew Hearn of the Health Promotion Agency said the products could easily be used to beat alcohol bans.
Some supermarkets in the UK had banned similar products due to misuse by youth and alcohol abuse.
Water Safety NZ manager Matt Claridge said anything that promoted the consumption of alcohol with water-based activities was irresponsible.