Mr Stott said .sucks seemed "frivolous" and potentially slanderous.
Despite reports of pop stars buying .sucks to forestall anyone who might want to ridicule them, the law also protected celebrities, he said.
"If, for example, someone wanted 'katemoss.sucks', she would have a path open to her to take [legal] action."
He said people or companies mocked by .sucks domains could probably hire intellectual property lawyers to take action under the Fair Trading Act.
Three of New Zealand's biggest companies - Spark, Fletcher Building and SkyCity - were asked if they would buy the domain names but didn't confirm or deny whether they planned to.
Taylor Swift and Kevin Spacey have bought the names.
The Internet Corporation for Assigned Names and Numbers (ICANN) started the Dot Sucks programme.
Liana Teo, ICANN Asia-Pacific spokeswoman, said trademark holders had an advance opportunity to register domain names corresponding to their trademarks.
But after that, the domain names became available to anyone.
The Vancouver Sun said Yahoo, Apple, and many others had paid big fees for a .sucks domain name.
This week, the Wall Street Journal said brands were being coerced into paying thousands of dollars for the domain names.
Earlier this year, Associated Press said an intellectual property advisory body representing major companies and industry groups sent a letter to ICANN asking it to halt the rollout of Dot Sucks calling it a "shakedown scheme" and "predatory".
