The Hawke's Bay DHB says Christopher Savage is not registered with the Medical Council, and it has informed police and the Ministry of Health that he is reportedly offering medical advice and treatment.

Hawke's Bay health authorities are warning the public not to take medical advice from a prominent Australian anti-vaccination campaigner who it says has been offering treatment in Napier.

Hawke's Bay DHB says it has been told Christopher Savage has been informing people he is a doctor and is offering medical treatment, despite not being registered with the New Zealand Medical Council.

The DHB says it has referred the matter to police and the Ministry of Health, and is urging the public not to follow any medical or treatment advice Savage might offer.

Australian media reported last month that Savage, a former Queensland police officer, had returned to Australia from Bali after local authorities there began investigating him over allegations that he was offering medical treatments for autism and other conditions.

News Corp reported that Indonesian authorities said they would investigate Savage for allegedly violating local health laws if he returned to the country.

Savage, who Australian authorities said had no registered medical training, had been in Bali for several months allegedly providing "services" he said he was not allowed to offer in Australia, according to News Corp.

Those services included intravenous infusions of magnesium and a chemical called DMSO, or dimethyl sulfoxide. He advertised the infusions and said he could treat problems that Western medicine was unable to fix.