GENEVA - David Goodall, a renowned 104-year-old Australian scientist who came to Switzerland to end his life, died on Thursday.

The ecologist and botanist died "peacefully" at 12:30 local time in Basel, from an infusion of Nembutal, a barbiturate, said Exit International, the group which helped him take his own life.

Switzerland is one of the few countries in the world to allow voluntary euthanasia in which a person is given a lethal drug to administer themselves through as assisted suicide process.

Goodall, who was born in London, England, left Australia last week, arriving in Switzerland on Monday after visiting relatives in France on his way.

He spoke to journalists at a hotel in Basel on Wednesday, saying he was happy to have the chance have his life "come to an end gracefully" in Switzerland but would have preferred to have it like that back home in Western Australia.

"The message I would like to send is: once one passes the age of 50 or 60, one should be free to decide for oneself whether one wants to go on living or not," he said, the Swiss News Agency, SDA-ATS reported.

Beethoven's Ode to Joy 9th Symphony was played to Goodall before he died after a last meal of fish and chips and cheesecake.

Assisted dying is illegal in Australia. except for in the state of Victoria, which in November 2017 voted to legalize euthanasia in some cases.

That law only comes into effect in 2019 and can only be used by those who are terminally ill or suffering from an incurable disease.

"My abilities have been declining over the past year or two, and my eyesight for the past five or six years, and I no longer want to continue life," Goodall said in Basel.

Swiss doctors are divided on the issue of assisted suicide.

The Swiss Academy of Medical Science has come out in favor of extending physician-assisted suicide to people living with intolerable pain even if they are not terminally ill, the Swiss newspaper Le Matin Dimanche reported on Sunday.

By contrast, the Association of Swiss Doctors (ASD) rejects widening the scope of physician-assisted suicide as this would remove doctors from the original goal of helping people suffering from an incurable and terminal illness.

Assisted dying, where patients engaged in ending their lives, can be legal in Canada, the Netherlands, Luxembourg, Switzerland and parts of the United States.