It might seem macabre to some but right-to-die campaigner Philip Nitschke says it's all in the name of science.

The founder of Exit International wants to be sure that a cheap and readily available substance that's fast emerging as a new choice for elected deaths actually delivers a peaceful ending.

Dr Nitschke says two Australians, both from Brisbane, used the substance to die in May. Read more

The South Australian Board of the Medical Board of Australia used its emergency powers in making the decision to "keep the public safe".

The measure is an interim action, separate to other inquiries the regulator is conducting into Nitschke.

The suspension came after an ABC story this month alleging that Nitschke had counselled a troubled, but otherwise healthy Perth man to take his life.

The man, Nigel Brayley, 45, died in May after taking an imported drug, which had been discussed at euthanasia forums run by Nitschke's Exit International.

Brayley attended such a forum in February.

But Nitschke argued he only had fleeting contact with Brayley, at a workshop and at a political rally.

Brayley acquired the drug before he had met Nitschke and had nothing to do with Exit International, the euthanasia campaigner protested.

The two did exchange emails prior to Brayley's death, in which his intentions were clear.

But Nitschke told reporters "There was nothing that I could or did say to Nigel that would have made him change his mind."

Nitschke said Brayley did not appear to be clinically depressed, and was instead under great stress because he believed the police were investigating him over the death of his ex-wife three years ago.

Nitschke later described the dead man as "a serial wife killer" and said his death was "rational suicide".

It has been reported also that federal police were investigating the disappearance of Brayley's former girlfriend in East Timor in 2005.

Dr Rodney Syme, an advocate for legal euthanasia under strict conditions, said doctors were ethically bound to try to dissuade a suicidal person from taking their life, and to report the matter to authorities.

Dr Syme said Nitschke's failure to do so may have triggered the suspension.

Nitschke told Guardian Australia the suspension was "very disappointing" and based on "different positions of ideology".

He said he would appeal.

But he said the suspension wouldn't stop him from his campaigning work.

Sources

• The Guardian
• ABC
• News.com.au
• Canberra Times
• Image: The Guardian