‘The voices told her to go in and ask to have a brain scan,’ says Dr Azuonye. ‘This was apparently for two reasons. She had a tumour in her brain and her brain stem was inflamed.

Because the voices had told her things in the past that had turned out to be true, she believed them when they said that she had a tumour. I requested a brain scan.’

It turned out the diagnosis made by the voices was correct. Interestingly, says Dr Azuonye, there were no clinical signs that would have alerted anyone — including the patient — to the tumour.

The surgeon suggested an immediate operation to remove the tumour, a decision the voices agreed with. ‘They said they would have preferred the operation to be done at the National Hospital, Queen Square, London, because they specialised in neurological diseases. But because she was already at the Royal Free Hospital, they told her to have the procedure done there because it was urgent,’ Dr Azuonye says.

After the operation, and when the woman had recovered consciousness, the voices returned one last time, to bid her farewell. ‘We are pleased to have helped you,’ they said, before bidding her goodbye. ‘It is a miracle,’ says Dr Azuonye. ‘The patient regards herself as being helped by a guardian angel.’

This story could be dismissed as a one-off, were it not for similarly miraculous cases which have come to light since the paper was published in the British Medical Journal.

Dr Azuonye was contacted by numerous other psychiatrists who had treated patients with similar experiences. These doctors feared for their careers if they went public with cases which defied conventional medical explanation. ‘Can you imagine what would happen if they told their clinical team a patient had been possessed by demons?’ says Dr Azuonye. ‘They’d be laughed out of court.’

One of the few types of miracle that can be investigated by science is the effect of prayer. And amazing as it sounds, prayer might just help to heal the sick. In a paper published in the scientific journal Annals Of Internal Medicine in 2000, researchers reported on 23 studies on various distant healing techniques, including prayer.

Thirteen of the 23 studies indicated a positive impact, nine found no benefit and one revealed a modest negative effect.

The U.S. National Institutes of Health, the equivalent of the UK’s Medical Research Council, is funding a huge trial to try and discover whether prayer works. Dr Mary Self from Cardiff is in no doubt it can miraculously heal the sick. In 1999 she was diagnosed with terminal bone cancer at the age of 34.

‘I was devastated,’ she says. ‘I was told there was no treatment that would cure it and that my illness was terminal. The bottom fell out of my world.’

Mary is a devout Christian and the congregation of her Baptist church began praying for her. Her condition continued to worsen.

For five long months her health became increasingly parlous and she began planning her funeral. She wrote letters to her two children to be opened after her death.

Day by day, hope evaporated for her, but more and more people joined her congregation in praying for a cure. Word of her struggle spread worldwide, but still Mary’s condition continued to worsen.

Her doctor gave her three weeks to live, but a miracle seemed to happen. A routine scan revealed the tumour had begun to shrink. Within three weeks it disappeared completely.

Robert Grimer, her surgeon at the Royal Orthopaedic Hospital in Birmingham, was stunned by the turn of events, and asked Mary how she thought it could have happened.