A Hillsborough County teacher resigned Wednesday after he was arrested on child pornography charges.

David Giberson, 68, resigned from his position with the school district after he was arrested, according to Hillsborough County School District spokeswoman Tanya Arja.

According to Tampa police, the investigation began after an iPod with "questionable" images was turned in to school security. At the time, no one knew who the iPod belonged to.

Officers responded to the scene and obtained a search warrant for the device, then discovered several hundred images of young boys on the iPod, Tampa police said.

The iPod was eventually tracked to Giberson's IP address, and detectives searched his home on Wednesday morning.

Police said Giberson admitted the iPod belonged to him, and he was arrested without incident. He is facing seven counts of child pornography.

Giberson had been with the district since 1980, Arja said. For the last four years, Giberson had worked as a peer evaluator, giving teachers tips on what they could do better.  He was not in direct contact with students while in that position.

The investigation continues. Additional charges may be pending.