A vast cache of child pornography (search) and photos of young priests having sex has been discovered at a Roman Catholic seminary, officials said Monday, leading politicians and church leaders to demand a criminal probe and the resignation of the bishop in charge.  

Bishop Kurt Krenn, who oversees the diocese, refused to step down, however, dismissing the images as a "childish prank."

Leaders of the Catholic diocese of St. Poelten (search) where the seminary is located, about 50 miles west of Vienna, spent much of the day in an emergency meeting.

The seminary's director, the Rev. Ulrich Kuechl, resigned along with his deputy, Wolfgang Rothe, the diocese said after the meeting. It did not elaborate.

As many as 40,000 photos and an undisclosed number of films, including child pornography, were found a year ago on computers at the seminary, the respected news magazine Profil reported.

It published several images purportedly showing young priests and their instructors kissing and fondling each other, and said others showed them engaging in orgies and sex games. The child porn came mostly from Web sites based in Poland (search), the magazine said.

Hannes Jarolim, a spokesman for the opposition Socialist Party (search), urged the Interior Ministry on Monday to launch a criminal investigation. Public prosecutor Walter Nemec said police were examining the material, which he said showed seminarians "in perverse situations together with their superiors."

The Austrian Bishops Conference issued a statement pledging a full and swift internal investigation.

"Anything that has to do with the practice of homosexuality or pornography has no place at a seminary for priests," it said.

Krenn, a conservative churchman, told Austrian television he had seen photos of seminary leaders in sexual situations with students, but he described the images as part of an elaborate prank that "had nothing to do with homosexuality."

His nonchalance drew swift and scathing reaction across the overwhelmingly Catholic nation.

"Collecting child pornography cannot be dismissed as a prank," said Thomas Huber, a Green Party politician.

In the mid-1990s, Austria was stung by allegations that Cardinal Hans Hermann Groer, who died last year, had molested students at an all-male Catholic boarding school two decades earlier. The affair had prompted Groer to step down.

A group of St. Poelten Diocese officials planned to ask the Vatican to remove Krenn as bishop, Austrian radio reported Monday. Martin Walchhofer, who supervises the alpine country's seminaries, said Krenn ultimately was responsible and "must answer before the church and before God for all of this."

Asked whether he intended to resign, Krenn said bluntly: "No."

The Vatican said it had no comment.

Krenn, 68, issued a statement calling the accusations groundless while conceding that he "may have made some wrong personnel decisions" at the seminary. Rothe, the former deputy seminary chief, was a legal adviser to the bishop.