A Moore Public Schools student attended school Thursday while "knowingly" had COVID-19, the school district said in a letter to parents Friday.
The unidentified student attended Westmoore High School.
The district said once it learned of the student's health on Thursday night, MPS alerted nurse and health department officials.
District nurses have completed contact tracing and have notified the staff, students and parents who may have been in close contact with the student.
MPS said the facility and classrooms have been deep cleaned and disinfected.
During the district's initial investigation, Moore Public Schools noted that the student's parent was mistaken about the student's end of quarantine date.