A Katy Independent School District junior high teacher has been arrested and charged with having an improper relationship with a student.

Authorities said Heather Lynn Miller, 46, was arrested Sunday evening at Katy Junior High School.

The district said Miller and the 14-year-old boy were found in her portable classroom by a Katy ISD police officer patrolling the campus.

Katy ISD officials said Miller, a social studies teacher, has been removed from the classroom and placed on administrative leave, pending a full investigation.

"The district takes this allegation very seriously and is fully cooperating with prosecutors," Katy ISD wrote in a letter sent to parents and staff. "Providing a safe and secure learning environment is and will continue to be our top priority, and we will always act swiftly when that is compromised. Likewise, we will continue to do everything we can to ensure the safety of our students."

The district said parents of students who may have been taught by Miller or interacted with her on a regular basis are being contacted directly by officials.

Miller posted $50,000 bond on Monday and was released.

She is due in court on Tuesday.