Original Article Mar 2, 1:17 PM EST Teacher indicted on charges he had affair with student TUCSON, Ariz. (AP) -- A former high school volleyball coach has been indicted on charges he had a sexual affair with a 15-year-old female student. Johnny Diaz, 25, faces two counts of sexual contact with a minor under the age of 18. He pleaded not guilty to the charges Wednesday. Diaz was a coach at Sunnyside High School in Tucson, but resigned in late January after police and school administrators began investigating the case. The suspected affair became known when another student told a school monitor about it, according to a report written by a police school resource officer. Officer Jeffrey Driscoll's report said neither the girl nor her mother wanted Diaz prosecuted. But after a review by the county attorney's office, the case was brought before the grand jury, Sgt. Decio Hopffer said. Diaz was placed on leave from the Sunnyside Unified School District as soon as the allegations came to light. He was hired in 2004 and pass all required background checks.