But Dr Nitschke has vowed to appeal the decision by the Northern Territory Health Professional Review Tribunal, saying doctors have to face the "harsh reality" that many people, including those who are not terminally ill, believe they have a right to end their own lives.

The tribunal ruled that the Medical Board of Australia's decision to use its emergency powers to suspend Dr Nitschke's registration last year was warranted. The suspension followed reports Dr Nitschke had supported Nigel Brayley, a murder suspect who was not terminally ill when he ended his own life last year. When Mr Brayley told him of his plans to end his own life, Dr Nitschke did not refer him to a medical practitioner.

In an appeal of the board's decision to the tribunal, Dr Nitschke argued he was not in a doctor patient relationship with Mr Brayley when they discussed end of life options and that people without a terminal illness could make a rational decision to commit suicide.

But in a strongly worded judgement, the tribunal said Dr Nitschke posed a risk to public health and safety because he interacted with large numbers of people considering suicide and his views might cause people to "follow the pathway to suicide believing it to be a pathway sanctioned by a medical practitioner and perhaps the medical profession generally".

It said his views may also mislead people about the values of doctors and undermine confidence in them.

In a written statement, Dr Nitschke said he was disappointed but not surprised by the decision which he was now appealing in the Darwin Supreme Court.

He said the tribunal's finding meant doctors were obliged to treat strangers they meet in a social setting, even if they are not in a state where they are permitted to practice medicine.

"A doctor who fails to do so is, in the view of the tribunal, a danger to public health and safety whose right to practice medicine must be suspended immediately," he said.

"The decision, if left unturned, creates a very dangerous precedent which applies to every Australian medical practitioner".

Dr Nitschke's barrister, Peter Nugent, said it was an error of law for the tribunal not to consider the "enormous body of medical literature addressing the issue of rational suicide". He expects the Supreme Court appeal to be listed for hearing in coming months.

Dr Nitschke said: "Voluntary euthanasia and rational suicide are very challenging issues for the medical profession.  It is cases such as this which will hopefully encourage the medical profession to face the harsh reality that the belief held by many elderly people, and some who are not, that no doctor has the right to tell them when they can or can't exit this life – can be rational and not a product of depression or mental illness."

"We might not like or agree with such decisions but they cannot be interpreted as meaning that person is depressed or mentally incompetent. Nothing could be further from the truth," he said.