A doctor who has been a ‘right to die’ campaigner for 30 years has been arrested for her part in a woman’s suicide in June.
Pro-euthanasia campaigners are using the arrest to call for a change in the law.
Dr Libby Wilson has been questioned by Surrey Police under suspicion of “aiding, abetting, counselling or procuring a suicide”.
The retired GP said she had spoken to Cari Loder, a multiple sclerosis sufferer, before her suicide on 8 June.
Dr Wilson said Cari “just wanted to make sure she had everything in order and to ask whether I had any final tips that might help”.
Dr Wilson added: “It’s not my business to persuade people to not commit suicide.”
Mrs Loder committed suicide using helium she had bought from the internet.
Dr Wilson is the founder of Friends at the End (Fate) which campaigns for a change in the law on assisted suicide.
She has co-written a book advising people how to starve and dehydrate themselves to death.
A spokeswoman for Fate said that the case showed the need for a proper debate in Parliament about assisted suicide.
Two other people have already been arrested on suspicion of helping Mrs Loder die.
Dr Wilson’s arrest is the first since the Director of Public Prosecutions (DPP) released guidelines for public consultation on prosecuting assisted suicide cases last week.
In July Dr Michael Irwin, who is an advisor to Fate, was interviewed by police over an assisted suicide that took place in Switzerland.
Dr Irwin gave 58-year-old Raymond Cutkelvin £1,500 towards killing himself at the Dignitas facility.
Mr Cutkelvin’s homosexual partner, Alan Rees, was also arrested in July on suspicion of assisting a suicide.
Dr Irwin said at the time: “I’ve done this before and I would do it again if someone is terminally ill”.
In the past twelve months top politicians have come out strongly against any attempt to legalise assisted suicide.
Prime Minister Gordon Brown said in December: “I believe that it is necessary to ensure that there is never a case in this country where a sick or elderly person feels under pressure to agree to an assisted death or somehow feels it is the expected thing to do.
“That is why I have always opposed legislation for assisted deaths.”
Last week David Cameron’s comments against assisted suicide, which he made three years ago, were re-affirmed by his spokesman.
He said the law should not be changed to allow doctors and others to “accelerate death”.
Mr Cameron added: “I think the long-term consequences of permitting such action are too likely to be dangerous for society.”
Jack Straw, the Justice Secretary, said in September: “I’m not in favour of changing the law.
“That would give a green light to assisted suicide, and my worry has always been the potential for abuse.”
A bid to change the law failed to attract sufficient support in the House of Lords recently.
At the time of the Lords’ debate Baroness Campbell of Surbiton spoke out against any weakening of the law.
She said: “Today I and hundreds of other disabled and terminally ill people want you to know, we do not want assisted dying to be legalised for ‘people like us’.”
She pointed out that: “Not one organisation of or for disabled and terminally ill people has campaigned for the changes proposed.”
She added: “They appear not to have noticed that the days of others knowing what is best for disabled and terminally ill people are past.
“We are now empowered and we know what we need to play a full part in society. We want help to live – not help to die.”