The Commerce Commission has fielded 67 complaints about traders falsely advertising products as protecting against the coronavirus.
Commission chairperson Anna Rawlings said cure and prevention claims range from ozone therapy as a disinfectant for living areas, to lanyards coated in chlorine dioxide that provide a protective barrier to viruses and bacteria.
"Nobody should be claiming something can provide a complete protection or a complete cure to COVID-19 itself. That would be of real concern to us," she said.
"We're working through the nature of the complaints to make sure we have a clear understanding of what's going on."
In most cases traders had removed potentially misleading claims from advertising, she said.
Last month, Medsafe warned people not to drink bleach, after revelations a website was promoting the chemical as a COVID-19 cure. The website has since shut down.
It is illegal for any person or business to make a claim about a good or service without substantial proof.
The complaints were received since the country went into lockdown in March.