David Goodall has fulfilled his final wish and taken his life through assisted suicide in a Swiss clinic, in a powerful statement in favour of voluntary euthanasia.

The story of the 104-year-old Perth academic, who is one of the first Australians to undertake the procedure due to old age rather than a terminal illness, has attracted international headlines and further inflamed a highly divisive debate.

His supporters applauded his decision to take charge of his fate after declaring his life was no longer worth living.

But critics warned his decision to end his life solely on the grounds of old age set a dangerous precedent

'It's my own choice'

The Perth great-grandfather departed Australia on Wednesday last week and spent time with family in Bordeaux, France, over the weekend, before travelling to the town of Basel in Switzerland, where assisted dying is legal.

He was greeted at the Swiss airport on Monday by euthanasia advocate Philip Nitschke, who helped the science professor and Order of Australia recipient fast-track his application to Swiss association Life Circle.

David Goodall is wheeled through the airport of the Swiss city of Basel by euthanasia campaigner Philip Nitschke ahead of his procedure to end his life. ( ABC News: Charlotte Hamlyn )

Ahead of his death, Dr Goodall said he resented having to travel so far to carry out his plan, but was relieved the end was near.

"My recent life has not been enjoyable," he said.

"I am glad to arrive [in Basel]. I'll be even more pleased when further steps of my journey are completed.

"I have been able to say goodbye. I was a bit sorry to say goodbye to my family in Bordeaux but that's the way it was."

When asked by a journalist whether he was certain he wanted to go through with his plan, Dr Goodall laughed and replied: "Oh yes, that's what I'm here for."

"I don't feel that anyone else's choice is involved. It's my own choice to end my life … and I look forward to that," Dr Goodall said.

"At my age, or less than my age, one wants to be free to choose the death when the death is an appropriate time."

A final performance

Overnight a press conference was called, with reporters from around the world packed into the small hotel room where Dr Goodall had been spending his final days.

As he was wheeled into the room, people were forced to shuffle equipment and clear cords out of the way to let him pass.

"There are more people here than I realised," he said as he passed through the press pack.

"I have been surprised that there has been such wide interest in my case."

When asked by media if he planned to listen to a particular song as he passed away, the veteran actor, singer and poet took the opportunity for one last performance as he broke into a rendition of Beethoven's Ode to Joy.

Sorry, this video has expired 104-year-old David Goodall sings the song he'd like played in his final moments

The performance was greeted with applause from the media pack as he finished.

Dr Goodall met with two Swiss doctors in the days leading up to his death, who confirmed his intention to end his life and that he was of sound mind, measures that are both required under Swiss law.

The fatal procedure, a lethal injection of the barbiturate Nembutal, was then carried out about 12:30pm local time on Thursday at the Life Circle/Eternal Spirit Foundation clinic in Basel.

Death a 'first' for euthanasia: Nitschke

Dr Philip Nitschke says Dr Goodall's case is unprecedented. ( AAP: Joe Castro )

Dr Nitschke, the founder of euthanasia advocacy group Exit International, said Dr Goodall's case was one of the firsts of its kind because, despite being frail, he does not have a terminal illness and is generally healthy.

"David is the first person I know of who fits the requirement of old age. It's a unique situation," he said.

"In some ways it's a form of elder abuse.

"You've got a situation now where a person is being told what they can and cannot do and they're simply trying to exercise what they see as an absolute right to be able to put an end to their life.

"This is an eminent and proud Australian. The fact that we are now, in a sense, forcing him to a foreign country to die, because this is what he really wants and passionately believes in, I think is something of an outrage."

A 'dangerous' precedent: AMA

But the Australian Medical Association expressed grave concerns about the precedent Dr Goodall's case sets.

A parliamentary committee in Western Australia is currently examining the issue of assisted dying, with a view to advising possible future legislation similar to that recently introduced in Victoria.

AMA president Michael Gannon described laws that allow euthanasia and physician-assisted suicide as "dangerous".

AMA president Michael Gannon says we should aspire to better palliative care. ( ABC News: David Weber )

"In many quarters we see the planned suicide of someone who's aged 100 celebrated," Dr Gannon said. "That concerns me.

"What is the age at which we no longer celebrate people continuing life?"

Dr Gannon said he was also deeply concerned with the reasoning Dr Goodall had expressed around his decision.

"People like Dr Goodall make a decision based on nothing more than they've decided there's nothing more to live for," he said.

"I think that's a dangerous line to cross."

"I have serious concerns about a community where we make arbitrary decisions about whose life is valuable enough to continue and whose should be ended under the law.

"A society should aspire to look after people who are struggling and to make sure that their lives are worth living.

"We should aspire to even better end-of-life care. We should aspire to better palliative care."

Sorry, this video has expired The curse of living too long

Family present to the end

Members of Dr Goodall's family, including five of his grandchildren, travelled from the US and France to say their final farewells.

For his family back in Perth, who said their goodbyes when Dr Goodall flew out last week, the finality of his decision was one they had been given time to come to terms with.

David Goodall's daughter Karen hugs her father before saying goodbye to him at Perth Airport. ( ABC News: Hugh Sando )

"I'm feeling very emotional but at the same time I'm at peace," daughter Karen Goodall-Smith told the ABC on the eve of his death.

"He has always felt that there is no point in being in this world — or surviving — if you can't make a difference, if you can't contribute to society.

"And in doing this so publicly he's made a huge contribution to the euthanasia debate."

Ms Goodall-Smith said she had spent the days since her father's departure reflecting.

"David has always been very humble … he never presents himself as being better than anybody in any way," she said.

"He didn't care what he looked like, where he lived, he didn't care about money, he didn't care about material things.

"He cared about science and knowledge and he cared about his family."

David Goodall with his daughter Karen and grandsons Chris (28), Matt (23) and Graham (25). ( ABC News: Hugh Sando )

Ms Goodall-Smith said she was, and had always been, proud of her father and would always be proud to be his daughter.

"He was an amazing scientist, an amazing man who did whatever he said he was going to do," she said.

"He was completely honest, straightforward and cared about humanity, cared about the world and making a difference.

"That's what I would like other people to remember him as."

Dr Goodall's family plan to hold a memorial in Perth in the coming months.