Central Islip, New York -- A former teacher at a school for gifted students who was accused of having scores of sexual pictures and videos of children was indicted Monday on 10 counts of possessing child pornography.

Michael Kelly Reiner, a longtime teacher at the Long Island School for the Gifted in Huntington Station, New York, was arrested and fired last month. He pleaded not guilty Monday in U.S. District Court in Central Islip and was to remain in custody until a Thursday bail hearing.

Prosecutors said they would argue against his release on bail. They said at least 70 still images and 42 video clips depicting children engaged in sexually explicit activities were found on his computers and hard drives.

Reiner's attorney, Ronald Schoenberg, said he would seek to have his client, who taught at the school for 18 years, released to his family.

He said Reiner, 46, never sought the child pornography and had not been accused of harming a child. He said Reiner had an "exemplary record."

"There's children who could be character witnesses for this man," Schoenberg said.

Reiner's home was searched after he aroused suspicion while crossing into Canada with a collection of photos showing boys as young as 4 posing in their underwear and bathing suits, prosecutors said.

The general counsel for the school, Linda Caputo Friedman, noted that the accusations against Reiner "happened privately; the school was not involved." Still, she said after his arrest: "We're horrified."

The school teaches 300 gifted children, from pre-kindergarten through the ninth grade.