LONDON — A German Roman Catholic cardinal claims the church "destroyed" documents in an effort to cover up sexual abuse that has engulfed the institution in scandal.

Cardinal Reinhard Marx spoke at a Vatican summit on Saturday, telling 190 church leaders that the harms inflicted on children in youth were the result of "abuse of power in the area of administration."

The four-day summit convened by Pope Francis aims to address the worldwide issue of sex abuse within the church. Saturday's discussions were dedicated to issues of transparency and breaking the code of silence that has kept abuse hidden.

"Files that could have documented the terrible deeds and named those responsible were destroyed, or not even created," Marx said. "Instead of the perpetrators, the victims were regulated and silence imposed on them. The stipulated procedures and processes for the prosecution of offences were deliberately not complied with, but instead cancelled or overridden. The rights of victims were effectively trampled underfoot, and left to the whims of individuals."

'Documents were manipulated'

Among Marx's recommendations included the redefining of confidentiality and secrecy within the church, publicly releasing statistics and details on abuse cases and publishing legal proceedings.

"The study indicates some documents were manipulated or did not contain what they should have contained ... no specific responsibilities," Marx told NBC News Saturday. "This refers to the Munich diocese, but I don't think the German case is an isolated one."

The summit began days after a formerly high-ranking American cardinal Theodore McCarrick was expelled from the priesthood after a Vatican investigation found sex abuse allegations against him were credible.

While church leaders considered hierarchical and procedural changes, survivors gathered in Rome to protest decades of cover-up and demanded accountability. They shouted "Zero tolerance!" as they marched toward the Vatican.

Among the marchers was Alberto Athie of Mexico, one of the first to accuse Legion of Christ founder Rev. Marcial Maciel of pedophilia.

'Mediocrity, hypocrisy and complacency'

The erosion of trust in the church is not lost on leaders.

In a letter to U.S. bishops last month, Francis said, "The Church's credibility has been seriously undercut and diminished by these sins and crimes, but even more by the efforts to deny or conceal them."

Sister Veronica Openibo, one of only a handful of women invited to the summit, reiterated the consequences years of abuse is having on the global congregation.

"A large number of Catholics are and will be angry and confused," she said. "We must acknowledge that our mediocrity, hypocrisy and complacency have brought us to this disgraceful and scandalous place we find ourselves as a church."