More than 50 priests in England and Wales have been defrocked for clerical sex abuse over the past 13 years, it has been revealed.
Figures show that 52 priests have been laicised - evicted from the clergy - since 2001 when new, tougher rules were put in place to protect children and vulnerable adults in the Catholic Church.
But the Church, which has been rocked by a series of historic abuse scandals, received many more hundreds of complaints of sexual misconduct against the clergy over just more than a decade.
And officials admitted that a reluctance among many victims to report abuse meant they have "no real knowledge" of its true scale.
A decade-long study by the National Catholic Safeguarding Commission (NCSC) shows that 487 allegations of sex abuse were made against members of the clergy from 2003 until 2012, while 31 more ministers were accused of having abusive images of children.
Of these, 203 are known to have been withdrawn from ministry, and 53 were convicted in a criminal court.
And there were 81 child protection allegations made last year - a leap from 59 in 2012.
Adrian Child, director of the Catholic Safeguarding Advisory Service, said the church had put in "robust measures" to tackle abuse, including making it mandatory for all allegations to be immediately reported to police.
And perpetrators who were not defrocked were subjected to "covenants of care" withdrawing them from ministering and severely restricting what they could do in the Church, he said.
There were 384 "covenants of care" in place by the end of 2013 in England and Wales with either a priest or a lay person.
But Mr Child admitted they still do not know the true scale of how many fell prey to abuse as many victims stay silent for decades, while others take the secrets of their abuse to the grave.
He said: "Often there is a time lapse of 20, 30, 40 years between the abuse and people coming forward.
"We have no real knowledge of how many people there might be who have been hurt in some way in the past."
And he cast doubt over claims recently made by Pope Francis, that one in 50 Catholic priests are paedophiles, applied to England and Wales.
He said: "That figure is not representative of the allegations against clergy in this country. The allegations we have had reported to us in this country are considerably lower than that."
Danny Sullivan, NCSC chairman, said the slew of celebrity sex abuse scandals which erupted in the wake of the late TV presenter Jimmy Savile's unmasking as a paedophile had encouraged victims to come forward.
"What you never know is when a victim will have the confidence to come forward and really feel they will be listened to and something will happen," he said.
"When the Jimmy Savile case broke, Napac, which supports adults abused in childhood, saw its calls rise from 200 a week to 2,000.
"In this world you don't know when people will come forward. It is about making sure everyone is in a safe environment."
He admitted trust in the Catholic Church had been shattered by "indefensible and inexcusable" failings to root out sex abuse, and it could take "a generation" for trust to be recovered.
And he threw his support behind calls to make it a crime to fail to report accusations of child sex abuse to the authorities, explaining that "if we are able to protect one person from this traumatic experience, it is worth it".
Some victim support groups gave a cautious welcome to the work the Church has done, but others called for far more action to encourage people to come forward.
Peter Saunders, chief executive of the National Association for People Abused in Childhood, said the defrocking of clerical abusers was "encouraging".
He said: "We cannot have people in this position of huge trust and responsibility being given free rein to abuse children or vulnerable adults. I know from personal experience having spoken to many victims that there is still work to be done.
"I am not heaping unfettered praise on the Church but clearly there is an element of giving some credit for what they (the Catholic safeguarding staff) are trying to do."
Anne Lawrence, former chairwoman of Minister and Clergy Sex Abuse Survivors, said the figures for the number of allegations received over the last decade represented the "tip of the iceberg".
She said: "There is nothing within the system in the Catholic Church, nothing that they have done, despite our repeated requests that they engage in a process in which they enable people to come forward at a higher rate than the national average.
"There is evidence that it is probably harder to speak out if you are from a Catholic background or a religious setting."