Belgian authorities on Monday raided three bishops' administrative offices as an official said investigators were nearing the end of a two-year probe into whether church officials protected child abusers at the expense of their victims.

Belgian Catholic Church spokesman Geert Lesage said the offices in the Hasselt, Mechelen and Antwerp cooperated during the raids and handed over requested files as much as possible.

A judicial official close to the investigation, who asked not to be identified because of the sensitivity of the issue, said Monday's surprise raids were based on some 200 witness accounts and 87 civil claims and sought to reveal if high-level clergy were involved in keeping abuse covered up.

Over the past two years, more than 500 witnesses have come forward with accounts of molestation by Catholic clergy in Belgium over several decades. One bishop was forced to resign in 2010 after he admitted he abused a nephew.

The main part of the investigation centers on "the non-assistance to people in danger and is targeted at people higher up in the hierarchy," the official said. "Possibly, we will be able to charge people." The official would not expand on who in the church hierarchy could potentially be charged.

"Today we saw the start of the final phase of Operation Chalice," the official said, using the investigation's code name. The official said the next step would likely be in a couple of months.

Tommy Scholtes, the spokesman for the Belgian bishop's conference said, "it is up to the judicial authorities to find out whether there has been negligence."

Church officials in both Mechelen and Hasselt said that several files taken Monday centered on the 1960s and 1970s. The cases are past the statute of limitation, but could still be used to show "non-assistance to people in danger," said Jeroen Moens, a spokesman for the Mechelen Bishops' office.

A tally of the raids showed that some two dozen files were collected from the three offices based on individual cases, reports of meetings between high clergy and victims and exchanges of letters.

The Belgian church is also leading an investigation into the allegations.

The raids were the first in "Operation Chalice" since June 2010, when authorities seized hundreds of case files from a church and used power tools to open a prelate's crypt in Mechelen's St. Rumbold Cathedral seeking evidence. Pope Benedict XVI called the raids "deplorable" at the time.

That raid was declared excessive by a Belgian court and based on premises that were too vague. But the government said the investigation could continue if the inquiry respects legal rules.

The judicial official stressed that "the context was totally different this time around."

In Hasselt, the files of four cases were taken, but church officials were allowed to take a copy first, said Clem Vande Broek, a spokesman for the Hasselt bishop's office. He said two of the cases dated from over 40 years back while the suspects involved had already died and were already known to judicial authorities.

"The whole procedure was correctly dealt with," said Vande Broek.

The judicial official said that copies were always allowed to be taken to allow the church to continue its own investigation.

The scandal has had a huge impact on the Belgian church and has highlighted the issue of sex abuse, which has undermined the church's credibility in many Western nations. Revelations of rape or other sexual abuse of minors by priests, and of cover-ups by bishops, piled up for months.

Belgium's abuse scandal broke when Bruges bishop Roger Vangheluwe admitted to the sexual abuse of a nephew for 13 years, starting when the boy was 5. He acknowledged briefly abusing a second nephew too.