At least six students at Fort Zumwalt East High School have had their cellphones seized by authorities for allegedly spreading nude pictures of their classmates.

Fort Zumwalt Superintendent Bernard DuBray said some female students took pictures of themselves “in various stages of undress” and sent them to a few boys, who forwarded those images to their friends.

“These guys, who have gotten their pictures, have been collecting them like someone might collect baseball cards,” DuBray said. The matter came to the attention of school officials this week, who turned it over to the St. Peters Police.

Police officials confirmed they are investigating the allegations, which involves a large number of teens at the school.

“We are investigating the alleged possession and distribution of child pornography due to juveniles sending nude photos of other students,” said Melissa Doss, public information officer for the St. Peters Police department. The cases will be sent to family court, which handles juvenile cases, in a couple of weeks, she said. Neither the district nor the police could say exactly how many students were implicated in the investigation.