prague | The only Jewish school in Prague has been plunged into crisis following the discovery of hardcore pornography hidden on the school’s Internet server.

Police are investigating the find, which involves sexually explicit images downloaded from as far back as December. The material was found some weeks ago by the school’s new Web site administrator.

An unnamed senior teacher recently was fired following the discovery at the Lauder Jewish Community School, which houses both a high school and an elementary school in a single building. The move sparked an angry reaction from the school’s teachers, who claim that their colleague had nothing to do with the material.

More than 20 teachers of a teaching staff of 28 went on strike this week to protest the dismissal, claiming that a Web site administrator previously connected to the school had claimed responsibility for the pornography.

The protesters are calling on the school principal, Vera Dvorakova, to resign.

“We are protesting because the teacher who was dismissed was not responsible for the material that was on the server,” teacher Katerina Dejmalova said. “We want Mrs. Dvorakova to resign and a new principal to be appointed.”

Dvorakova was not available for comment.

The issue has made it to the highest levels of Prague’s Jewish community, which founded the school in 1997. Senior Jewish community representatives voted last week not to remove Dvorakova from the school, which is partly funded by the Ronald S. Lauder Foundation.

The teachers, who say they have the support of the vast majority of pupils, agreed to halt their strike temporarily after learning that George Ban, vice president and CEO of the Lauder foundation, will visit Prague to try to resolve the situation.

This is the second major crisis to engulf the school in recent months. Last April, dozens of students, teachers and parents demonstrated outside the Jewish community’s headquarters in a heated dispute over the selection of Dvorakova as principal.

The demonstrators claimed that the city’s Jewish leaders had imposed their own choice of principal, and suggested that the selection process had not been handled fairly. They also called for “stability” at the school, which has had four principals since the start of the school session last year.