The Catholic Church has said that a pilgrim was cured in Knock for the first time.
The announcement is the culmination of decades of campaigning by Marion Carroll.
The grandmother from Athlone claims that she experienced a "miraculous cure" at the National Marian Shrine 30 years ago.
Mrs Carroll was a mother in her late 30s in 1989 when she was brought on a stretcher on the annual pilgrimage to Knock of the diocese of Ardagh and Clonmacnoise.
She says she told a statue of Our Lady of Knock that Mary must know what it was like for a mother to suffer greatly.
Supported by her husband, Jimmy, and others, she has stated that she was using a wheelchair, confined to her bed much of the time, doubly incontinent and showing symptoms of Multiple Sclerosis.
After her plea to Our Lady of Knock for understanding, Mrs Carroll claims her health was immediately transformed and that she began to walk again.
But the head of the Medical Bureau at the Knock shrine, Dr Diarmuid Murray, told RTÉ News that no definite diagnosis of her condition was available, leading her diocesan authorities to adopt a wait-and-see attitude to her claim.
The file on her case was reviewed in her presence last January by the doctor along with her local bishop Francis Duffy of Ardagh and Clonmacnoise, Archbishop Michael Neary of Tuam in whose diocese Knock is located, two priests and Mrs Carroll's husband, Jimmy.
Minutes of the meeting record Dr Murray quoting from a letter from a consultant gastroenterologist stating that having reviewed Mrs Carroll's medical file, "regardless of whether her condition is organic or psychological, the dramatic improvement from the time of her visit to Knock is unexplained."
The consultant added: "My feeling is that her improvement is very unlikely to be explained by conventional medical wisdom".
A consultant neurologist who reviewed the file wrote to Dr Murray that "it would be fair to say she has been cured of neurological symptoms but not of MS. It seems to me that Mrs Carroll had medically unexplained symptoms which have now (thankfully) resolved."
Today, leading his diocese’s annual pilgrimage to Knock Basilica, Bishop Duffy announced to the congregation, which included Mrs Duffy, her husband, their three children and other relatives, that he does not doubt that "there was a healing, a cure of the illness that beset Marion for several years".
"Marion came here on that September day (in 1989) with a bleak future. Marion's book 'I Was Cured at Knock’ describes her words to Our Lady that morning: 'You are a mother too and you know how I feel about leaving my husband and children’. It wasn’t a prayer, it wasn’t a statement, it was one woman chatting to another."
"On that special day, Marion recalled the key moment during Benediction and Blessing of the Sick: 'It was at that time I got this magnificent feeling - a wonderful sensation like a whispering breeze telling me that I was cured. I got this beautiful, magnificent feeling telling me that if the stretcher was opened I could get up and walk'."
"And so Marion did," Dr Duffy added.
"I recognise that Marion was healed from her long standing illness while on pilgrimage in this sacred place. Marion’s healing is good news for her, for her husband Jimmy, for her family and friends. Marion’s healing is life changing.
"Many have attested to the dramatic change that came about in Marion here and on her return to Athlone in 1989. Without doubt there was a healing, a cure of the illness that beset Marion for several years.
"Marion was liberated from sickness and its impact on her and on her family. It is also a healing for which there is no medical explanation at present, it is definite and yet defies medical explanation."