Ahead of Pope Francis' four-day summit on preventing clergy sexual abuse, the Vatican has admitted there are secret rules for priests who father children, despite their vows of celibacy. 

The New York Times was first to report Monday on the existence of the Vatican guidelines. 

Vatican spokesman Alessandro Gisotti acknowledged to the Times and other outlets that the guidelines exist and that "it is a document for internal use." The spokesman wouldn't reveal specifics, but told the Times the guideline "requests" that the father leave the priesthood to "assume his responsibilities" as a parent. 

Vincent Doyle told the paper he was 28 when he found out a Roman Catholic priest was actually his biological father. 

Doyle explained an archbishop first showed him the secret document while he was searching for justice for children of priests. 

Doyle explained to the Times that when he asked for a copy, the archbishop said that couldn't happen, because it was a secret. 

Doyle went on to found a group called Coping International, to try and support fellow children of priests. According to Doyle, there are kids like him "everywhere" and he believes the issue is "the next scandal" for the Catholic church.