ATOKA, Oklahoma - A teacher and coach at Atoka High School was arrested and charged with several felony counts following an investigation into allegations he gave better grades to students in exchange for sexual favors.

The Oklahoma State Bureau of Investigation says Casey Hauff, 32, turned himself in to the Atoka jail Friday morning.

In October 2011, allegations surfaced of sexual misconduct between Hauff and several students.

During their investigation, OSBI agents identified five female victims. Agents say Hauff told many of the students he would increase their grades if they performed sexual acts.

Agents say many of those sexual acts happened at school during school hours. Agents say Hauff also asked the victims to send him nude photos of them on his cell phone.

The Atoka County District Attorney's Office has charged Hauff with 11 felony counts, including two counts of second-degree rape, one count of forcible sodomy, four counts of solicitation of a minor, two counts of sexual battery, one count of showing obscene material to a minor, and one count of lewd or indecent proposal to a child under the age of 16.

Hauff's bond has been set at $250,000. The OSBI believes there are victims of Hauff who have not been identified. Anyone with information is asked to contact the OSBI at 1-800-522-8017.