A GP has been charged and will now have to give a consent form to all his patients, after falsely claiming he could cure cancer with green tea.

Dr William Barnes, a Perth-based practitioner, had claimed on his website that his “non toxic herbal and nutritional treatment” was an “alternative treatment for cancer”. The scientifically suspicious claim has cost him $25,000.

The treatment reportedly consisted of oral or intravenous administration of green tea polyphenols, vitamin C, curcumin from turmeric, quercetin, genistein from soy beans, selenium, as well as dubiously-touted “anti-cancer herbs”, and “mineral replacements”.

Dr Barnes’ treatment followed an analysis of hair samples and diet, the Medical Board of Australia said in its orders.

“At all times while the advertisement was maintained… neither the treatment alone or in combination was recognised by competent medical practitioners or oncologists as proper or effective treatment for cancer,” the board said.

“There was no sound scientific basis upon which the respondent could truthfully represent to patients, prospective patients and members of the public the claim that the treatment could cure cancer.”

The MBA said the greatest risk was that a cancer sufferer might delay effective treatment by getting involved in Dr Barnes’ green tea hokum.

The WA doctor has been professionally reprimanded and banned from advertising unproven cancer treatments. He will also pay the $25,000 fine.

All Dr Barnes’ patients will now read a consent form stating that he supports “treatment provided by oncologists [including] chemotherapy and other drug therapy”, but makes sure the patient “understand[s] that there is no evidence that taking any of these substances or receiving them intravenously will cure my cancer or slow the progression of my cancer.”