Authorities will not seek criminal charges stemming from a recent sexual assault allegation at Anderson High School, officials said Tuesday.

Officials from the Travis County District Attorney's Office and Austin Independent School District police confirmed they do not have sufficient evidence to proceed with a case, according to a letter being sent to parents Tuesday afternoon.

The reported incident happened in mid-September, but officials have been reluctant to release many details, citing an on-going investigation.

At the time, school officials said the incident was confirmed to two students and that the campus was not at risk. They added that the case did not involve a staff member or intruder.