The Huntsville City School District is being investigated by the U.S. Department of Education over claims of harassment.
Officials say a JROTC instructor at Grissom High School told students that homosexuality is sinful.
GLBT Advocacy and Youth Services, an Alabama nonprofit, filed a complaint with the Department of Education in October.
In their complaint, the organization says the school district failed to prevent and stop harassment.
The school district received a letter from the department of education this week.
District officials say they will work with the department of education's office of civil rights to provide any assistance they need with the investigation.
Copyright 2012 The Associated Press.