Sir Terry Pratchett has defended his documentary about assisted suicide, which showed the death of a millionaire hotelier who was suffering from motor neurone disease.
In the BBC Two film, the 63-year-old writer, who has Alzheimer's, went to the Dignitas clinic in Switzerland to see the man take a lethal dose of barbiturates.
Asked why he wanted to make the film, the Discworld author told BBC Breakfast: "Because I was appalled at the current situation. I know that assisted dying is practised in at least three places in Europe and also in the United States.
"The Government here has always turned its back on it and I was ashamed that British people had to drag themselves to Switzerland, at considerable cost, in order to get the services that they were hoping for."
The film, In Choosing To Die, followed Peter Smedley, 71, from his mansion in Guernsey to the Dignitas clinic, which over the last 12 years has helped 1,100 people to die.
Sir Terry said: "Peter wanted to show the world what was happening and why he was doing it."
Sir Terry described the moments after Mr Smedley took the poison, saying he was struck by the "incongruity" of the situation.
"He said to me 'Have a good life'. And then he shook (my PA) Rob's hand and said 'Have a good life, I know I have'.
"And then he started thanking the members of the crew while he was dying and was embarrassed at the end because he couldn't remember the name of the sound man.
"And you think 'How British is this?'
"You can tell in the film that I'm moved. The incongruity of the situation overtakes you. A man has died, that's a bad thing, but he wanted to die, that's a good thing."
Director Charlie Russell said it was ultimately the BBC's choice to screen the film.
He said: "As a film-maker I felt that it was the truth of the matter. Unfortunately we do all die. It's not necessarily very nice but that is what happens to us all so I think it is quite important to see it."
Sir Terry added: "I think you have to take into consideration the fact that Peter was so open about everything.
"He wasn't timid. He was almost, I would say, in charge.
"We didn't try to make it charming or anything like that."
Campaigners have accused the BBC of helping to promote assisted suicide but the broadcaster has said the programme gives viewers the chance to make up their own minds.
A Dignity in Dying spokeswoman, who has described the documentary as "deeply moving and at times difficult to watch", said she believed the publicity before the programme had helped.
"People who did not want to watch it did not have to watch and were not confronted with something they did not want to see," she said.
She added: "It certainly shows that Dignitas is not an ideal option for people and we would rather people had the choice of dying at home at a time and in a manner of their choosing."
But anti-euthanasia campaigners have complained about the film's portrayal of assisted suicide.
Alistair Thompson, a spokesman for the Care Not Killing Alliance pressure group, said: "This is pro-assisted suicide propaganda loosely dressed up as a documentary."
Mr Thompson accused the BBC of repeatedly giving voice to pro-euthanasia views and claimed this is the fifth BBC programme in three years presented by a pro-euthanasia campaigner or sympathiser.
He said: "The evidence is that the more you portray this, the more suicides you will have."
The BBC has denied it had any bias in the public debate over the issue.
A spokeswoman said the documentary was "about one person's experience, Terry's journey exploring the issues and the experience he is going through.
"It is giving people the chance to make their own minds up on the issue."
Former Bishop of Rochester, the Rt Rev Michael Nazir-Ali, claimed the programme was "propaganda on one side".
"I think an opportunity had been bypassed of having a balanced programme - the thousands of people who use the hospice movement and who have a good and peaceful death, there was very little about them," he told BBC Radio 5 Live.
"This was really propaganda on one side.
"Life is a gift and it has infinite value and we are not competent to take it, we do not have the right to take it, except perhaps in the most extreme circumstances of protecting the weak.
"What we do have the right to expect is a good, caring, pain-free, peaceful death and, of course, in this century, in the last 100 years, there have been tremendous strides made in providing just that.
"That was simply not there."
Dr Peter Saunders, campaign director for the Care Not Killing alliance, said: "We felt the programme was very unbalanced and one-sided and did not put the counter-arguments.
"Our biggest concern was that it really breached just about all the international and national guidelines on portrayal of suicide by the media.
"We are very worried about the danger of copycat suicide or suicide contagion."
He added: "We have written to the Secretary of State for Health and the Secretary of State for Culture to ask them to carry out an urgent investigation into the way that assisted suicide has been covered by the BBC and its link to English suicide rates."
A BBC spokeswoman said: "Following the programme, we had 82 appreciations and 162 complaints, bringing the total number of complaints up to 898.
"The aim of the programme was to create discussion and this is clearly a subject that resonates."
An Ofcom spokesman said they had received "barely a handful" of complaints.