'I don't think I have forgotten [to do] anything ... the letter to the judge, to my family, that's all.'

She added: 'I am happy to be going away, honestly. I am going to go slowly.'

With that she closed her eyes and slipped into a deep sleep from which she never woke up.

At her bedside in her modest flat in Alicante, southern Spain, sat a man and a woman from the pro-euthanasia group Association for the Right to a Dignified Death. Leonor and Jorge (not their real names) are now both wanted by the police for helping Madeleine kill herself.

The death of the former French model, who was once the muse of Belgium's famous singer-songwriters, Jacques Brel, sparked a euthanasia controversy in her adopted home, Spain, where committing suicide is illegal. Leonor and Jorge face up to 10 years in prison for helping her to die.

And a police investigation is under way after Madeleine's angry son Domingo Biver demanded those who helped her be tracked down and punished.

Her son believes she was given to depression and encouraged to kill herself by the pro-euthanasia volunteers.

Madeleine had suffered from the fatal amyotrophic lateral sclerosis, commonly known as Lou Gehrig's disease, for five years and before she committed suicide by taking an undisclosed drug she explained in a letter and an interview to a Spanish newspaper why she was ending it all.

'I have lived well. But one night I fell because my legs failed me. They had to put plates in them eventually so I could move. I was more or less stuck in a bed until I would die.'

She said she was also tortured by the effects of the fatal motor neuron disorder, which left her with 'a body like an overcooked piece of spaghetti'.

Confined to a wheelchair, she quickly became dependent on others for everything.

For Madeleine, the prospect of a slow, debilitating death was a stark contrast with the glamorous, adventurous life she lived as a young woman in bohemian Paris in the 1950s.

A regular in the fashionable haunts of the city, she inspired Madeleine, one of the famous songs that Brel, who lived most of his life in France, wrote.

She recalled: 'We were young, free and without cares. Three of us would go into a bar together and 20 of us would come out.'

The orphan child of a communist father and Jewish mother killed in occupied Paris during the second world war, she narrowly escaped being transported to a concentration camp.

At 15, she became the teenaged bride of a French mercenary and lived off modelling underwear in post-war Paris. Four years later she divorced him. She eventually moved to Alicante with the man who later became her husband.

After nursing him through an agonising death, Madeleine regretted not heeding his desperate pleas for her to remove his drips and tubes and end his pain. So when she was diagnosed four years ago, Madeleine did not want to go the same way.

Though her son Domingo, 35, lived close by, this fiercely independent woman could not stand being a burden on him.

'I cannot even lift my grandchildren any more with my arms. I will soon be a burden on everyone. They found me a home nearby but I don't want someone to clean my backside,' she said.

In the weeks before she died, Madeleine wrote an emotive letter to the newspaper El Pais in which she defended her right to 'die with dignity'.

She wrote: 'Please give me a glass of water, wine or whisky. I want to die with my head held high, blowing kisses to those who have helped me with their love and words. This is not a crime. It is not a murder.'

But before she died two weeks ago, she did have one final wish.

'I'd love to see my husband again. We could have another row. That would be great.'

For Leonor it was the first time she had volunteered to help someone commit suicide.

But though nervous, she remained coolly determined to help a person she believed wanted to escape a desperate end.

Leonor had experienced being at the side of a friend who died slowly and in agony.

The experience inspired her to join the Association for the Right to a Dignified Death in an effort to save others from that fate.

Both Leonor and Jorge spent days with Madeleine before she died on January 12.

Just before she took a fatal dose, Jorge says he tried to persuade Madeleine to think again. He said: 'Why don't we wait another day, just so we can chat some more?'

But he says Madeleine was determined. 'I have made my mind up and am prepared.'

They promised to take away her plants and most importantly to put a few drops of her favourite perfume, Opium, on her neck before she died.

The volunteers say helping someone to die is hard. The day after Madeleine's death, Leonor burst into tears as she put one of the plants on the terrace of her home.

Jorge has a more idealistic attitude. 'When someone is about to die, it is like a liberation for them, from what they have been suffering,' he says.

The Association for the Right to a Dignified Death, which sent the two volunteers, defended its actions.

Fernando Marin, president of the group, said it was 'not against the law to offer moral support to someone who is determined to commit suicide. That is what we do.'

Mr Marin claims his group is not the only supporter of euthanasia.

Eight out of 100 doctors in Spain admit giving lethal drugs to people who were suffering terminal conditions and asked to be killed, according to a survey.

And 60 per cent of doctors said they were in favour of doctor-assisted euthanasia, according to another survey.

One doctor who visited Madeleine at the request of the pro-euthanasia group said she had thought through why she wanted to end her life.

'Her case is exceptional for her level of planning and serenity. There are people who plan it but haven't thought it through,' said the unnamed doctor.

'They try to escape suffering but they have usually suffered a lot by then. Madeleine has not; she wanted to stop that happening in the future.'

The Catholic Church in Spain likens euthanasia to abortion and insists both are sins. Some disabled rights groups also condemn legalising the right to suicide, claiming it would make their lives harder.

But despite a virulent campaign against it, a survey found 70 per cent of Spaniards were in favour of legalising and regulating it.

The government, which has introduced a number of radical social reforms in the once-strictly Catholic country, has failed to honour a promise to open a commission on euthanasia.

But despite the Socialist government's best efforts to sidestep this controversial issue, it will not go away.