The purple, powdered rice in question: Alfa PXP Royale Proponents say PXP, made from a purple rice grown in Thailand, is ground to the size of an "alfa molecule", enabling it to "feed the mitochondria in the cells". According to a 2007 promotional brochure, Alfa PXP's "potent antioxident" qualities work to "neutralise" the free radicals that cause cancer, heart disease, Alzheimer's, stroke, diabetes – indeed, "all" degenerative diseases. It can also, it claims, help with wrinkles and other signs of ageing. For $150 a month, customers can buy a one-teaspoon-a-day supply from Ms Winterstein's website. However, she urges customers to take two or even three teaspoons a day, for three months, to feel the supposed benefits. It is slightly cheaper to sign up for a wholesale amount of the powder, delivered monthly, and cheaper again if customers sign up to onsell the products. Those who sell PXP are offered the prospect of bonuses and luxury rewards.

Loading Dr Senaka Ranadheera, a food scientist from the University of Melbourne, said that purple rice does contain significantly more antoxidants than white rice, which can help prevent a number of diseases. However he said these benefits can be gained by simply eating the rice with a meal, and did not necessarily require specialised and expensive powders. Supermarkets sell purple rice, also known as black rice, for about $10 a kilogram. Enzacta, the company behind PXP, lists its office as an address in Wyoming, USA. But with hundreds of businesses listed to the same small office, it appears Enzacta's headquarters are little more than an office postbox. The company has a meticulously low profile in Australia, but salespeople scattered across the globe.

After The Age and The Sydney Morning Herald contacted the company via its website, Max Cottle, the company's national sales director in Australia and New Zealand, got in touch. Mr Cottle claimed he had been healed of polycythemia (a slow-growing blood cancer that thickens the blood) when people prayed for him. Since then, he said, he had been taking PXP powder and had not suffered so much as a cold. Taylor Winterstein Emma Robbins, a New Zealand PXP salesperson who recruited Ms Winterstein to the company, stressed the scheme was not a pyramid scheme but a multi-level marketing company that ran on a "dual binary system". Ms Winterstein, she said, was taking a break from selling PXP to focus on her workshops.

. Credit:Matt Golding Ms Winterstein's Tay's Way Movement has previously attracted controversy for her $200-a head Making Informed Choices shows, which spruik scepticism about vaccinating children against communicable diseases. As well as raising fears about so-called "vaccine injuries", the workshops canvass anti-vaxxer parents' options for daycare and preschool, given state and federal no-jab, no-play laws. Ms Winterstein did not respond to a request for comment. Melbourne surgeon John Cunningham, who has been awarded an Order of Australia for his work promoting vaccinations, said Ms Winterstein represented the "sinister version of the modern mumtrepreneur".