Tens of thousands of children have been victims of sexual abuse by the Roman Catholic Church in the Netherlands since 1945, an independent commission said on Friday, criticising what it called the church's cover-up and culture of silence.

Church leaders said the findings filled them with shame and sorrow and offered a heartfelt apology, as not only the perpetrators were to blame, but church authorities too.

The commission estimated 10,000 to 20,000 minors were sexually abused in Catholic orphanages, boarding schools and seminaries between 1945 and 1981, with offences ranging from very mild to serious, including rape.

Education changes meant few Catholic homes for minors remained after 1981, but abuses involving the church continued.

Several tens of thousands of minors were subjected to mild, serious, and very serious forms of inappropriate sexual behaviour in the Roman Catholic Church, from 1945 until 2010, the commission said.

Most cases were of mild to moderate abuse, such as touching, but it estimated several thousand instances of rape.

The findings appear to show abuse was more widespread in the Netherlands than in Ireland, in a scandal that has rocked the Catholic Church in Europe and the United States and forced Pope Benedict to apologise to victims.

The church committed crimes against humanity, said Bert Smeets of Mea Culpa, an organisation to help victims.

The investigation was commissioned by two Catholic bodies, the Conference of Bishops and the Dutch Religious Conference, in 2010 after cases surfaced involving paedophile priests in the Netherlands, Belgium, Ireland, Germany, Australia, Canada and the United States.

Abuse by Catholic priests, laymen and laywomen was systematically covered up by the church to protect its reputation, the commission said, adding that the church was guilty of inadequate supervision and inadequate action.

The Catholic Church had a culture of not airing its dirty laundry, said Wim Deetman, a Protestant former education minister and former mayor of The Hague who led the commission.

SHAME AND SORROW

In a joint statement, the Conference of Bishops and Dutch Religious Conference (KNR) said the report fills us with shame and sorrow, and offered a heartfelt apology.

The perpetrators are not the only ones to blame. Church authorities who did not act correctly and did not give priority to the interests of and care for these victims also share in this blame. We deeply regret this abuse, they added.

But the most widely awaited response was that of Cardinal Ad Simonis, a former archbishop of Utrecht. Asked on Dutch television last year about reports of widespread abuse, he said: we didn't know about it, the phrase used by Holocaust-deniers.

Cardinal Simonis said the commission had painted a bleak picture of the nature and extent of sexual abuse in the Catholic Church. He appeared to accept some responsibility for what had happened under his leadership, saying he had erred in appointing men who had abused minors.

About 28 percent of the population is Catholic and 18 percent Protestant, while 44 percent are not religious.

Until the 1960s, the Netherlands was segregated along religious fault lines with separate schools, universities, unions, broadcasters, sports clubs and political parties for Catholics and Protestants, and remnants of segregation remain.

The commission said child sexual abuse was no more prevalent in Catholic institutions than in ones run by other groups but was twice as high as the national average of 10 percent.

Sexual abuse of minors is widespread in Dutch society, said its report, based on statements of victims who came forward as well as a survey of 34,234 Dutch nationals aged 40 and above.

BISHOP CRITICISED

A new complaints committee set up to handle sexual abuse in the Catholic Church will give priority to complaints about at least 105 perpetrators who are still alive, the commission said.

Its report singled out Ronald Philippe Baer, Bishop of Rotterdam from 1983 until 1993, for particular criticism, saying he appointed unsuitable men to the priesthood who were guilty of abusing minors, and turned a blind eye to their offences.

How the bishop at the time, Monsignor Baer, could have responded so lightly to the (conditional) conviction of one of these priests is a mystery to the Commission, it said.

Baer, now in his eighties, went to the Belgian monastery of Chevetogne after he stepped down in 1993, the Rotterdam diocese says on its website, adding he was admitted to hospital in March for heart problems.

In a statement, the Dutch prosecutors' office said it had received 30 reports of abuse by clergymen but the cases had lapsed because the alleged crimes took place too long ago.

It said the Deetman commission had referred 11 cases to prosecutors of which one was being investigated, while the others contained too little information and had probably lapsed.

So far, one sexton, or church officer, has been sentenced to 15 months in jail, while two other cases had lapsed, prosecutors said.

The commission has already published some recommendations.

It has urged the Church to pay compensation of between 5,000 and 100,000 euros ($6,500-$130,500) each to victims and to set up a centre to help those abused.

You can assume that all the dioceses, all the congregations, all the orders will pay compensation to the victims, Wim Eijk, the archbishop of Utrecht, told reporters.

(Additional reporting by Liza Jansen in The Hague; edited by Richard Meares)