Thousands of children suffered sexual abuse in Dutch Catholic institutions, and church officials knew about the abuse but failed to adequately address it or help the victims, according to a long-awaited investigation released Friday.

Archbishop of Utrecht Wim Eijk apologized to victims on behalf of the entire Dutch Catholic organization and said the report "fills us with shame and sorrow."

The report said Catholic officials failed to tackle the widespread abuse, which ranged from "unwanted sexual advances" to serious sex abuse, in an attempt to prevent scandals.

The investigation followed allegations of repeated incidents of abuse at one cloister that quickly spread to claims from Catholic institutions across the country, echoing similar church-related scandals around the world.

An independent commission said Dutch Catholic officials failed to tackle the widespread abuse at church institutions. (Hazir Reka/Reuters)

The suspected number of abuse victims who spent some of their youth in church institutions likely lies somewhere between 10,000 and 20,000, according to a summary of the report investigating allegations of abuse dating back to 1945.

The commission received some 1,800 complaints of abuse at Catholic schools, seminaries and orphanages and said that the institutions suffered from "a failure of oversight." It then conducted the broader survey of the general population for a more comprehensive analysis of the scale and nature of sexual abuse of minors — both in the church and elsewhere.

Based on a survey among more than 34,000 people, the commission estimated that one in 10 Dutch children suffered some form of abuse broadly in society. The number doubled to 20 percent of children who spent part of their youth in an institution like an orphanage or boarding school — whether Catholic or not.

The commission was set up last year under the leadership of former government minister Wim Deetman, who said there could be no doubt church leaders knew of the problem.

"The idea that people did not know there was a risk ... is untenable," he said.

Deetman said abuse continued in part because the Catholic church in the Netherlands was splintered, so bishops and religious orders sometimes worked autonomously to deal with abuse and "did not hang out their dirty laundry."

However, he said the commission concluded that "it is wrong to talk of a culture of silence" by the church as a whole.

Bert Smeets, an abuse victim who attended the presentation of the report, said it did not go far enough in investigating and outlining in precise detail exactly what happened.

"What was happening was sexual abuse, violence, spiritual terror, and that should have been investigated," Smeets told The Associated Press. "It remains vague. All sorts of things happened, but nobody knows exactly what or by whom. This way they avoid responsibility."

Archbishop Eijk said victims would be compensated by a commission the Dutch church set up last month and which has a scale starting at €5,000 ($6,725 Cdn) and rising to a maximum of €100,000 ($134,500 Cdn depending on the nature of the abuse.

He said he felt personally ashamed of the abuse. "It is terrible," he said.

The commission said about 800 priests, brothers, pastors or lay people working for the church were named in the complaints. About 105 of them were still alive, although it was not known if they remained in church positions, the report said. It did not release their names and identified them as "perpetrators" rather than "offenders," meaning they had not been proven to have committed a crime.

Prosecutors said in a statement that Deetman's inquiry had referred 11 cases -- without naming the alleged perpetrators -- to them.

Prosecutors opened only one investigation based on those reports, saying the other 10 did not contain enough detailed information and adding that they also appeared to have happened too long ago to prosecute. Had the case files contained enough information to trigger an investigation, prosecutors could have asked for the identities of the suspected abusers.

Deetman said the inquiry could not establish a "scientific link" between priests' celibacy and abuse, but he added, "we don't consider it impossible ... maybe if there was voluntary celibacy a number of problems would not have happened."

According to the Dutch Central Bureau for Statistics, 29 percent of the Dutch population of 16 million identified themselves as Catholics in 2008, making it the largest religion in the country.