GRAND PRAIRIE -- A teacher at Grand Prairie High School has been arrested for allegedly having an improper relationship with a student.

The district said Friday that Derek Fuller, who teaches Algebra I, was removed from teaching after being informed of the event on Jan. 26.

Police opened an investigation, which led to Fuller's arrest on May 18.

<p>Grand Prairie High School Algebra I teacher was arrested Thursday, May 18, 2017 for having an improper relationship with a student back in January 2017. (GPISD)</p>

"This kind of conduct is outrageous and will not be tolerated," GPISD Superintendent Dr. Susan Hull said. "The teacher-student relationship is sacred. It reflects a vow from teachers to parents that their children are safe -- as safe as they would be at home.

"When a teacher at Grand Prairie ISD breaks that vow, he or she will be dealt with quickly and aggressively. I encourage law enforcement to to pursue all available action."

Grand Prairie police have charged Fuller with having an improper relationship with a student, as well as aggravated sexual assault.

His bond is set at $125,000, and GPPD says the case is still "very active."