Fr Tom Ingoldsby of the Salesian Order accused patients of the complementary therapy of “opening the door to evil and occult forces which have later side effects”.
But the Reiki Federation of Ireland (RFI), which regulates the training and practice of the healing method, dismissed the outspoken cleric's views as being rooted in ignorance and suspicion.
Father Ingoldsby made his remarks in his 'Fast Food for the soul': in the Open Door newsletter, which is distributed free to 5,000 homes each week in the West Dublin and North Kildare area.
Reiki teacher and RFI co-founder Angela Gorman said it was understandable that some people remained sceptical about complementary therapies but she warned them not to be close-minded to new ideas.
“Some people's opinions of Reiki are often anchored in ignorance and suspicion rather than pure scientific fact,” said Ms Gorman, a former nurse.
Father Ingoldsby wrote in his column: “Many people today are falling for Reiki unaware that they are on a dangerous road, as once the door is opened to Satan, it is extremely difficult to get him out.
Father Ingoldsby, who is based near Portlaoise, went on to cite the case of a Catholic man who reported migraine pain after receiving Reiki treatment: “A priest discerned by prayer that there had been evil channelled into him,” Father Ingoldsby claimed.
Ms Gorman, who has been teaching Reiki for over a decade and appeared on Rte Late Show last year to defend the therapy, said it was becoming increasingly mainstream in society.
Many public figures like the Prince of Wales openly support the healing method's benefits. Addressing the World Health Organisation in May, Prince Charles encouraged doctors to take a more holistic view by putting great emphasis on preventative healthcare.
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