Surrey Police are investigating the case of a doctor who helped terminally ill people from Britain to travel to a Swiss clinic to commit suicide.
Dr Michael Irwin was struck off the medical register last year for obtaining drugs to help a friend die.
He admits that in the last two years he has given advice and encouragement to five terminally-ill people to fly from England to Zurich's Dignitas clinic.
It is the clinic which helped British woman Anne Turner to die on Tuesday.
Dr Irwin told BBC Radio Four's Today programme: "In the past two years, I have given advice and encouragement and counsel to five terminally-ill people to go from England over to Dignitas in Zurich.
"Am I breaking the law? If they had committed suicide in this country, the answer is yes. However they got to Switzerland, but they could have changed their minds, they could have been rejected by Dignitas."
Surrey Police interviewed 74-year-old Dr Irwin last August, and they have confirmed that their investigation continues.
The maximum penalty for aiding and abetting suicide in England and Wales is 14 years in prison.
Dr Irwin, a former UN medical director and head of the Voluntary Euthanasia Society, has already received a police caution for his actions.
He has also accompanied a patient from Scotland, where there is no specific law against assisted suicide.
He told Today: "Suicide was never a crime in Scotland - so there is no crime of aiding and abetting and of counselling suicide under Scottish law.
"And I hope that I will be questioned by the police, because I think this would be a very fascinating medical legal situation."
Dr Irwin was struck off the medical register by the General Medical Council last September.
Dr Turner had a progressive degenerative disease
He told Today: "My only medical crime was to write a single prescription for a Class C drug in my name, intending to give this to a friend of mine on the Isle of Man who was dying - rather slowly - from cancer of the prostate.
"In the end, he was too ill to take the pills that I was able - or willing - to give to him.
"I did not show any remorse when it came to my actual hearing before the GMC - in fact, I challenged them on this issue by saying that all good doctors should be compassionate to help similar patients in these situations."
He said the GMC's decision to strike him off the medical register meant nothing to him as he was already retired, and that he was not afraid to go to prison for his beliefs.
Since the Dignitas clinic was set up in 1998, more than 450 people from across Europe have ended their lives there, including more than 40 from Britain.
Opponents of assisted suicide say it is wrong to take human life in this way - and argue that good quality palliative care is the right approach.
On Tuesday, retired doctor Anne Turner took her own life with the help of doctors at the controversial Swiss clinic.
Dr Turner, 66, from Bath, had a progressive and incurable degenerative disease called supranuclear palsy.
She could only walk with a stick and faced a future in a wheelchair.
Dr Turner's condition, which also afflicted comedian Dudley Moore, also left with her with badly slurred speech, and she had some difficulty swallowing.