A New Zealand doctor who advised a woman to treat her eating disorder with "self-pleasure" or masturbation is under investigation by the Medical Council. The general physician, who was not named for purposes of privacy, has been found to show a "lack of judgment" while caring for a patient in a span of five years.

According to Health and Disciplinary Commissioner Anthony Hill, the patient was suffering from several health problems including anxiety, bulimia and obsessive compulsive disorder. In a report, Mr Hill said the doctor had "frequently discussed" masturbation with the patient while making comments about her body.

The woman said in her testimony that the doctor had made sex-related comments "either every time or every second time she saw him." She revealed her doctor would use suggestive words and lead the conversation to the subject of masturbation.

The doctor had allegedly told the woman she should be pleasuring herself "often" so it will "make her smile." The woman said the doctor had also recommended "therapeutic use of sexual behaviours", deep abdominal massage and low pressure water enemas for her eating disorder.

The woman was also prescribed medication with "known risk factors" over the years including a possibility of accidental overdose. Mr Hill said the continued prescription of zopiclone, a drug usually taken for insomnia, put the woman at risk due to the doctor's "unsafe and poor practice."

The New Zealand doctor was found to have violated the Code of Health and Disability Services Consumers' Rights. Mr Hill said several aspects of the GP's treatment were found to be "not clinically appropriate."

The report further indicated that the doctor's treatment plan of abdominal massage and enemas were not supported by medical literature but instead might "reinforce" the focus on the patient's bulimia.

Mr Hill reiterated that the repeated discussion of masturbation and the frequency of "inappropriate" comments breaching sexual boundaries including the trust between doctor-patient. He added that the doctor should have referred the woman to a specialist since he was recommending treatments beyond his expertise.

According to reports, the doctor has written a letter of apology to the patient. The Medical Council will review the doctor and place him under the watch of two senior colleagues.