Brian Clement, a Florida nutritionist who treated two First Nations girls with leukemia in 2014, is back giving lectures in Ontario and promoting supplements that are illegal in Canada.

Advertisements for his speaking engagements say the owner of Hippocrates Health Institute (HHI) will be selling his proprietary brand of supplements, LifeGive, at Six Nations and several other locations in Ontario.

CBC News has learned LifeGive is not licensed to be sold in Canada. Supplements must be licensed and approved by Health Canada's Natural and Non-Prescription Health Products directorate before they go on sale.

Health Canada says anyone selling unlicensed supplements could face a fine and have their products seized.

CBC News found LifeGive supplements for sale at the healthEnut cafe, a raw food franchise with locations in Milton and Georgetown, Ont.

One supplement, called Conscious-Brain, sells for $77 a bottle. HHI's website claims it contains nutrients "that have been empirically linked to the reduction of memory loss, dementia, and Alzheimer's."

HeathEnut owner Susan Wilson said she has been selling the supplements since her store opened six years ago and had "no idea" they were not licensed in Canada.

"I did not know that this was illegal," she said.

Wilson says the product will be removed from her shelves immediately.

Brian Clement is scheduled to speak and sign autographs at her cafe this weekend. He is also due to appear at a wellness fair at Six Nations near Brantford, Ont., followed by lectures in Toronto and London, Ont., next week.

'Reverse cancer'

Clement has come under fire for other dubious health claims. At his last lecture on Six Nations in 2014, he claimed his institute had "more people reverse cancer than any institute in the history of health care."

He also said that no matter what disease you're afflicted with, "you just have to have the will to heal yourself."

CBC News first investigated Clement after his clinic treated two First Nations girls from Ontario battling leukemia. Makayla Sault attended Clement's 2014 lecture on Six Nations and was later treated at HHI after quitting chemotherapy at a Hamilton hospital. The 11-year-old died in January 2015.

The mother of the other girl, J.J., who cannot be identified, also attended the lecture. She told CBC News she decided to withdraw her daughter from chemo treatment at McMaster Children's Hospital to attend HHI after Clement told her leukemia is "not difficult for them to deal with."

Clement denied those claims.

J.J.'s case resulted in a landmark court decision. The judge ruled it was the mother's Aboriginal right to choose traditional medicine. The controversial decision was later amended and the judge clarified that although Aboriginal rights must be respected, the best interests of the child are paramount.

According to the family's lawyer, the girl is no longer being treated by HHI and is back in chemotherapy.

Following a CBC News investigation, Florida's Department of Health fined Clement and ordered him and his wife to stop "practising medicine without a licence." The investigation was later dropped because of "insufficient evidence."

Supplements targeted at cancer patients

According to a 2010 Ipsos Reid survey, approximately three-quarters of Canadians regularly take natural health products such as vitamins, minerals, fish oil and herbal remedies. Annual sales in Canada total about $1.4 billion.

Another LifeGive supplement, Chemozin, is targeted specifically at cancer patients, and purportedly "supports the cellular system during and after the use of chemotherapy," HHI says.

"Save your money and stick with real medicine," said Dr. David Gorski, an oncologist from Detroit, Mich., and editor of the blog Science-Based Medicine.

"He presents zero evidence that it's true," he said. "There's nothing we would consider acceptable evidence in medicine."

CBC News requested an interview with Clement but we have not received a response.