Roman Catholic priests take vows of lifelong celibacy. Probably the majority see it as a gift and a calling, and are content to sacrifice a sexual relationship and a family life for the sake of their ministry.

However, for some, a vow made with every good intention is not so easily kept – and sometimes children are the result. In historically Catholic countries like Ireland, this can result in terrible tensions, with the natural desire of parents to bring up a child together at war with shame, social disapproval and a desire for secrecy. Almost inevitably, it is the children – and often their mothers – who come off worst, with the children not told the identity of their fathers.

Six months ago, a new website aimed at helping support such children was set up in Ireland and has already received around 15,000 hits. It's a project of COPING – Children of Priests International – which was founded to help children come to terms with their experiences. It has had visitors from the United States, Italy, India and Australia as well as from Ireland, implying a widespread need.

The co-ordinator of COPING – whose father was a priest – told Christian Today: "The main problem is secrecy. Men who are priests and women –in the case of nuns – who wish to maintain appearances for their own personal sake, indirectly impose upon the child, the same secret that they wish to keep."

He pointed to a recent case involving a priest "deliberately scolding a mother, admonishing her, 'not allowing' her to tell the truth for fear of societal repudiation". "Pressures include imposed secrecy, confusion, bullying, scaremongering, placing the agenda of clericalism ahead of the welfare of a child. Thus an adult centred church exists, not child centred, which in effect is no form of church at all," the co-ordinator said.

Another issue is the confidentiality agreements imposed on women who have borne children to priests in order to silence them, which he described as "unethical". The Irish Bishops have declared them to be unjust if they "compromise the consent of the parties" and if they "hinder the basic goods of the child".

The co-ordinator referred to other pressures faced by priests' children, saying that while their position need not be problematic, other people's reactions often made it so.

"My own dad always brought me about with him and people seemed to somehow accept it, subtly acknowledging the relationship but it still could not be named," he said.

"One case we know of includes a priest who flew his child abroad but insisted on his adult child agreeing that he was a distant relative and the father barely acknowledged his child for the duration of their stay. This is very damaging. Others remain cool and aloof and detached, some others warm and appear affectionate.

"It boils down to this one question; what is more important, perception of reputation or the wellbeing of an individual child?"

The co-ordinator said that it was not automatically right for the priest to leave the priesthood when he fathered a child. "I personally, as the son of a Catholic priest am quite proud of my father for his work," he said. "However, nothing should stand in the way of a child's development and to put ministerial work ahead of the rights of a child is certainly unethical and undermines any goodness afforded by the same ministry."

He concluded: "If you are a woman who has had a child by a priest / religious, and so on, I urge confidence. COPING will support you in making representation for justice. To the children: you are more than a secret, you are a human being and let nobody tell you any different. If you are a priest, do the right thing by your child, if you have one; if you cannot do this, leave down the collar for you do not deserve to wear it. Where is the sin, to father a child or to hide the child?"

The website includes testimonies from children of priests and their mothers, including women whose lovers had died and who felt unable to tell their stories to anyone, including their children.

It has won backing from the Catholic Church and cites the support of the Archbishop of Dublin, Most Rev Diarmuid Martin, who said: "I pray that COPING will be able to find ways which will bring the children of priests and their natural parents together for the benefit of both." Its website also quotes Pope Francis, who as Cardinal Bergoglio said: "If a priest comes to me and tells me that he has gotten a woman pregnant...I remind him that the natural law comes before his right as a priest...just as that child has a right to his mother, he has the right to the face of his father."

The Irish Catholic Bishops Conference has said: "The Bishops are anxious to ensure that appropriate support is being offered to all children. In particular they appreciate the sensitivity required in any pastoral outreach to children of priests."

Referring to the Church's counselling programme, the statement says: "The Bishops are actively collaborating with Towards Healing so that Towards Healing will be in a position to provide appropriate counselling / support to children of Catholic Clergy."