A number of Catholic priests in Ireland have been specifically trained to carry out exorcisms in response to a growing demand from parishioners.

At least three practising clergymen have been taught how to perform the ancient ritual on people who believe they have been possessed by demonic spirits, according to a spokesman for the Catholic Church.

Fr. Fiontán Ó Monacháin, secretary to the Archbishop of Tuam, has lifted the lid on the secretive world of exorcists in a new documentary, which will be screened on TG4 tomorrow night (Sunday).

He said: "When someone approaches us with a request for an exorcism, they usually approach their parish priest first.

"That priest would have a good idea if it's a psychiatric or a spiritual issue. If it's a spiritual problem, the priest would usually say prayers or celebrate Mass in the house, or give a special blessing using holy water.

"If that doesn't work and if they are still suffering, a formal exorcism may be necessary. And if that's the case there are priests in the country who are trained in that field.

"There aren't many. I know of a Jesuit priest in Galway and there is another priest in the Killaloe Diocese and a Franciscan priest from Carlow.

"We refer people to those priests and the Bishop gives them permission to carry out the exorcism."

Fr Ó Monacháin also said that demand for exorcisms from practising priests had increased over the past decade.

He added: "Perhaps it has become more popular again as there has been more demand for it in the last ten years. This is evident from the requests priests are receiving."

The documentary, "Díbirt Deamhain," also explores the growing number of people seeking exorcisms from spiritual healers who are not part of the clergy.

Members of the New Charismatic Movement and a former Irish soldier-turned-Shaman tell the programme's makers of their sometimes terrifying experiences with possessed people.

The documentary also recounts the factual story of two Irish seminarians who deemed themselves possessed by demons and threw themselves from the same window in St. Patrick's, Maynooth, 19 years apart.

Trainee priest Sean O'Grady fell to his death from the third-floor window of Rhetoric House in 1941, but the second seminarian, Thomas McGinn, survived long enough to explain how he was tormented by demons.

An exorcism was performed in the room, after which the wall between the room and corridor was knocked down. The window was subsequently removed and a statue of St.Joseph was erected in its place.