Philip Nitschke says he wouldn't have sent a man who wanted to end his life because he was a suspect in his wife's murder "off to a psychiatrist".
Euthanasia campaigner Philip Nitschke denies he went too far in helping a fit and healthy but depressed man end his life.
Perth man Nigel Brayley, 45, died in May after taking euthanasia drug Nembutal, because he feared he would be charged with his wife's murder.
His former wife Lina, 37, died in February 2011 after she fell from the top of Statham's Quarry while taking photographs.
Her death was initially believed to be an accident, but, after Mr Brayley died, it was revealed he was being investigated for his alleged involvement in her death.
Dr Nitschke said in a statement on Thursday that Mr Brayley had attended an Exit International workshop in Perth in February and purchased the banned Peaceful Pill eHandbook.
He said it was "a clear case of rational suicide".
"While Exit may not condone his reasons for taking this step, we fully support his right to be able to exercise this option."
Dr Nitschke defended his handling of the matter.
"I support his right to have access to that information and ultimately those drugs," Dr Nitschke said on Fairfax radio on Friday.
"It looks as though he did it to prevent a worsening situation which he detailed in the email he sent to me. He was looking at significant financial loss, he was looking at some dreadful outcome but didn't explain why.
"In retrospect, it looks as though he was fearful of a long period of incarceration.
"A person that's confronting that sort of dire circumstance, can well, I would argue, make a clear rational decision that death might be the preferred option.
"I don't think we should define that person as sick and certainly we shouldn't be sending him off to a psychiatrist."
Beyondblue chairman Jeff Kennett labelled Dr Nitschke's actions reprehensible.
"Equally unacceptable is Dr Nitschke's comment that he did not see it as part of his responsibility to refer the young man to an appropriate specialist for further treatment," Mr Kennett said.
"As a long-time supporter of euthanasia for the terminally ill, for those for whom the dignity of life has been lost, and under special conditions, I believe Dr Nitschke's latest act has crossed the line of decency and professional conduct.
"He has done his more general cause for euthanasia a great deal of harm."
Dr Nitschke said it would be a case of "paternalistic medicine" if he had insisted Mr Brayley seek psychiatric help.
"I didn't give him his drugs - I simply gave him information and he went and did it."
Mr Brayley illegally imported the Nembutal from China.
He also dismissed the suggestion it was inappropriate to assist a man involved in a legal matter.
"Whether we should have somehow kept him alive so he could face the court is a rather strange way of looking at it."
* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or MensLine Australia on 1300 78 99 78