Acupuncturists are disputing a study which says many of them break the law with online claims they can fix mental illness, infertility, and arthritis.
The study published in the New Zealand Medical Journal found more than 100 acupuncture websites may be in violation of the Medicines Act.
The study claimed 101 websites gave examples of what acupuncture can prevent or alleviate without providing robust evidence.
Section 58 of the Medicines Act prohibits the publication of such claims, unless they are true. The list of conditions in the Act includes alcoholism, cancer, infertility and mental disorders
Study author Daniel Ryan, of the Society for Science Based Healthcare, said claims that acupuncture could prevent or treat mental illness, arthritis and infertility were the most common. These claims combined appeared on 73 percent of the 101 websites.
"Words like treat, cure or prevent should be a big no when there's no strong evidence. People have the right to make informed choices and they shouldn't be misinformed if there isn't any evidence."
NZ Acupuncture spokesperson Kate Roberts said some acupuncturists may be in breach of the Act, but not as many as the research suggests.
"This study is a fairly poorly-executed word search using Google, and it didn't look specifically at the context or therapeutic claims made on the website, it simply looked at words mentioned.
"There's actually no prohibition for a medical condition to appear on the website."
But, Mr Ryan said he did cross-reference his search with treatment claims, not just conditions listed.
The Medical Association, which publishes the New Zealand Medical Journal, says the study was peer-reviewed by three independent experts and it stands by the publication.
Ms Roberts said many acupuncturists' websites used The Acupuncture Evidence Project as proof.
Released in February this year, it compared the last four years of systematic reviews and meta-analyses from the PubMed and Cochrane Library databases.
Of the 122 conditions reviewed, evidence was found at varying levels for all but five conditions.
Ms Roberts said looking on a website was a very small part of the decision-making process. "It's usually either based on the evidence or on personal recommendations or recommendations of other health providers. They will only really use a website to find a location of a suitable practitioner."
ACC examining acupuncture effectiveness
ACC subsidises acupuncture treatments on referral from doctors or other qualified health professionals.
Last year the organisation spent $34.9m on acupuncture session subsidies.
ACC spokesperson James Funnell said the organisation relied on patient choice and the judgement of medical professionals to determine the best course of treatment, and sometimes acupuncture was recommended.
Mr Funnell said ACC was doing its own review of acupuncture's effectiveness. "It will examine the effectiveness, treatment exposure, and safety of acupuncture for a variety of musculoskeletal conditions."
Health law expert Adam Lewis said the The Acupuncture Evidence Project appeared to be a strong piece of evidence in showing acupuncture was not just a "theatrical placebo".
He said it was likely the Project would stand up in court as a defence to breaching the Medicines Act.
A total of 150 websites were reviewed for the study.
Acupuncturists are voluntarily regulated by the groups New Zealand Acupuncture and the NZ Acupuncture Standards Authority.