Image caption Officials said they were searching for evidence of possible abuse

Roman Catholic bishops in Belgium have expressed their disappointment at a police raid on the offices of a Church commission investigating sexual abuse.

Bishops' conference spokesman Eric de Beukelaer said the confiscation of the commission's files violated victims' confidentiality and hindered its work.

Investigators also seized material from the Church's headquarters and the home of the former archbishop of Belgium.

The country is one of several where the Church has been shaken by abuse claims.

In April, the Bishop of Bruges, Roger Vangheluwe, resigned after admitting he had sexually abused a boy more than 20 years ago.

'Really shocked'

On Thursday, the police carried out a series of raids as part of an investigation into allegations of abuse committed by priests.

The Church's headquarters, the Palace of the Archbishop of Mechelen-Brussels, was sealed off, while officers searched for related material. Bishops meeting there were barred from leaving the premises or telephoning outside for several hours.

What am I supposed to say to someone who gave me information expecting discretion? Peter Adriaenssens, Church commission on abuse

Officers also raided the nearby home of the recently retired archbishop of Belgium, Cardinal Godfried Danneels, seizing paperwork and his computer.

The Vatican has named a successor to Roger Vangheluwe as bishop of Bruges.

Jozef De Kesel is currently the bishop of the Bulna diocese and an auxiliary at the church headquarters raided by police on Thursday.

In Leuven, investigators seized all 475 dossiers from the offices of the Church commission tracking complaints and compiling evidence about clerical sexual abuse. The computer of the commission's chairman was also taken.

"It was not a pleasant experience, but everything proceeded in a correct manner," Mr De Beukelaer said, adding that no-one was questioned.

The spokesman reaffirmed the Church's readiness to co-operate with the authorities on abuse cases, but expressed regret at the confiscation of the commission's documents.

"This violates the right to confidentiality of victims who have contacted the commission," he said. "Such acts greatly complicate the necessary and excellent work of the committee."

The commission's chairman, Peter Adriaenssens, said he was "really shocked" that the officers had taken all of the dossiers without telling his staff the focus of their investigation.

"Now we are a commission without dossiers, without materials. On Monday we will meet to decide what to do," he told a news conference.

"What am I supposed to say to someone who gave me information expecting discretion?" the child psychiatrist asked.

Prosecutors said the object of the search was to gather evidence about alleged abuse "by a number of people within the Church".

The Catholic Church in Belgium has apologised for its silence on abuse cases in the past and its new leader, Brussels Archbishop Andre-Joseph Leonard, has promised a policy of zero tolerance.