The American Civil Liberties Union challenged religious groups' access to Kentucky elementary schools on Thursday. It targeted all 174 public school superintendents.
The ACLU requested they provide information about how groups are granted access to schools to distribute literature to students during school hours.
The Open Records Act request specifically mentioned Gideons International, a group dedicated to Bible distribution.
ACLU of Kentucky Executive Director Michael Aldridge commented on the investigation.
"Directing the religious upbringing of one's own children is one of the most fundamental rights a parent can have," he said. "When government officials, including school officials, take it upon themselves to usurp that parental prerogative, they exceed their governmental authority and undermine religious liberty."
Aldridge added, "The ACLU of Kentucky fully supports the rights of all religious groups to promote their message of faith. Government officials, however, cannot allow our public elementary schools to be used by others to promote one religion over another."