Dr Philip Nitschke managed to overcome opposition to his latest tour / PA

The euthanasia campaigner insists his aim is to save lives

Illegal drugs from China in doses large enough to kill up to three adults are being ordered over the internet and taken by Britons opting for suicide, a controversial campaigner told an audience in York yesterday.

Dr Philip Nitschke, dubbed Dr Death, was telling his audience of more than 30 about those in the UK and elsewhere who are ignoring the law to order fatal drugs and take their own lives.

This will be the last group the Australian euthanasia campaigner talks to on his four-stop tour from London to Scotland. Some are old and frail, some are just over 50, but almost all have come to hear about the techniques available for planning their own death.

Among them was a reporter for The Independent, who heard Dr Nitschke explain how people are ordering banned barbiturates over the internet from China in doses large enough to kill.

Discussing how one particular drug was used to aid sleep before it was banned in Britain, Dr Nitschke joked: "They found it had a side effect – death. A few teaspoons meant a good night's sleep. A few more and no one would ever wake up."

Drinking alcohol could speed up the effects. "But most don't have time to finish their whisky. If you have an eloquent last speech, plan to make it before you drink [the drug]."

Sharing jokes about accidental death and spoken suicide notes is hardly the norm for the small Priory Street Centre in York – which is more at home hosting business conferences and training workshops. Yet the audience yesterday were reading leaflets on various drugs and gases that can be used to commit suicide.

They were told a powdered dose of one drug could be flat-packed into an innocent-looking envelope and get through customs.

"China is now illegally selling the drug in powdered form in a big way," Dr Nitschke said, quoting an example of a large shipment of 25 grams bought via mail order for about £575.

Nineteen women and 17 men attended yesterday's meeting although many left after the public presentation rather than pay £40 for the following three-hour workshop.

Retired barmaid June Capaldi, 75, told The Independent: "I don't want my kids and grandchildren seeing me hanging out of a chair in a retirement home with my mouth open and no teeth. I have already written to them all saying I don't want to be resuscitated but if I can get hold of this drug I will have it."

The tour had been widely condemned by church leaders, Christian groups and disabled people. Dr Nitschke first visited Britain in 2008 but that tour was left in tatters when venue after venue pulled out at the last minute.

This time around the schedule, focussing on areas with elderly populations, went ahead as planned as opponents failed to persuade venues to pull the plug.

Dr Nitschke, who has admitted helping four people to die, insisted his aim was to save lives.

He argued that once people had a means of killing themselves, many who might attempt a botched suicide would instead prolong their lives, knowing they had a way out without having to call on a loved one to help, exposing them to the risk of jail.