The woman, indentified only as 'Jane', described it as the "final act of love" when she injected her father with an overdose of an anaesthetic drug as he lay in a hospital ward 10 years ago.

Assisting a suicide is illegal under a 1993 law and anyone found guilty could face 14 years' imprisonment. Charges have only been contemplated in one other case -- that of Dublin woman Rosemary Toole Gilhooley, who was assisted in taking her own life by American, the Rev George Exoo.

However, Irish authorities were unable to secure the extradition of Mr Exoo from his home in west Virginia. Gardai are now carrying out initial inquiries in the call to determine whether charges should be brought against the unidentified woman.

It is thought that Jane is employed in healthcare, as she told RTE's 'Liveline' that she had access to the drug through her work.

She said her father had terminal cancer and had been enduring terrible pain for around six months before she administered the fatal injection without the knowledge of the rest of her family.

When asked if she had covered up her action, she replied "there wasn't any need".

"I was visiting my dad. I administered the drug. I slipped away home quietly, sadly, but happy in another way that he was gone.

"My mother was rung to say my dad had died -- hours later. But I knew hours beforehand that she was going to get that news."

Jane said she had confided in a priest but had told no one else of what she had done. She added that, while she was aware it was a criminal act to participate in euthanasia, her priority was helping her father.

"I've often thought about that, if it came to light, I'd be prepared to face the consequences. I wouldn't put my fear of whatever the consequences may be before my love for my dad and my knowing that I wanted his pain to stop," she said.

Jane said she had discussed it with her father beforehand and that he was worried she might get into trouble if she helped him die.

"He didn't ask me in any words like 'put me out of my agony'. He told me that he wouldn't want to linger, that he wouldn't want to be in pain and that he would love to be able to slip away peacefully and quietly and I offered to help him."

She said her father had been collecting his tablets for several weeks and was hiding them in his bedside locker. When she found the medication and confronted him, he replied: "I want to make an exit."

"I was told by the doctors treating him that he was dying slowly but surely, and that described it perfectly. He had no dignity -- bedpots; he was wasting away, he couldn't eat, he was on a drip... He was in a room in a hospital where there were six other people dying of cancer, with just curtains between them.

"I got the needle, I inserted it into the tube on the drip which was going into his hand. He took a little breath and he was gone," she said.

Speaking to the Irish Independent afterwards, Claire Mulqueeny, from Newbridge, Co Kildare, whose son, Vernon, has multiple sclerosis, said that the decision about when a terminally ill person dies should be a personal choice.

Mrs Mulqueeny has agreed to help her 42-year-old son to end his life if that is what he choses to do.

"I told him 'I hope that day never comes, but if that's what you want, I'll do it'. We wouldn't advise it for everyone, because life is precious. But, like that woman, if people have made such a decision and they're just a shell of their former selves, and they have made that decision before they get really bad, well then you want to help them."