A Melbourne doctor who says he has been prescribing injectable medications to patients seeking to end their lives wants police to prosecute him so that he can argue the case for euthanasia in court.

Appearing on Monday night's Q&A, Rodney Symes admitted to giving two of his patients Nembutal — a barbiturate, or sleep-inducing drug that is commonly used by veterinarians to euthanase animals — to assist their suicide.

He said he had hoped his actions would prompt a test case where he could put forward his arguments for Australia's laws against euthanasia to be amended.

"I have openly gone and stated to the police that I have given a man Nembutal," he said.

"I have described the circumstances in which that happened.

"At the end of the day, the policeman said to me very kindly: 'I don't think there is enough evidence to prosecute.'"

But Dr Symes said while police had conducted a coronial inquest on one occasion, no prosecutions had yet been made against him.

"I've had policeman come into my home after I have given medication to a woman," he said.

"As they walked down the door to interview me, they said: 'Don't get alarmed doctor, this is just for a coronial inquest, not for a prosecution.'"

Actions simply 'very, very good palliation'

Dr Symes has been an advocate for physician-assisted dying for nearly 20 years, and the president of Dying With Dignity Victoria for 10 years.

He argues that providing a patient with Nembutal offers them a more complete and effective form of palliation than the painkillers often administered to patients in palliative care, such as morphine or midazolam.

"I would argue what I am doing in providing somebody with medication, is providing them with very, very good palliation," he said.

"I argue that I can provide a person with medication which provides them with palliation, relieves the psychological and existential suffering which they have when they are facing a dreadful death — I believe that is a palliative act."

He said amending Australia's euthanasia laws would provide comfort to the few Australians that are unable to control the way they die.

"I think it is absolutely imperative that a person who wants to end their life engages with their family, gets them to understand why they need to consider making a decision like this," he said.

"The vast majority of people die dignified, peaceful, comfortable deaths — if you can use that word — in the presence of their family having drawn their life to a close in the way most satisfactory for them.

"We are talking about 98 per cent of predictable deaths in this country.

"The debate we are having about euthanasing individuals is to a very small percentage of the population."