Carroll ISD is being investigated by the U.S. Department of Education Office for Civil Rights over complaints that were filed involving students.

The office has opened three investigations into the district, CISD and the office both confirmed. Because the complaints involve students, details about the nature of the investigations have not been disclosed.

“Our district is fully cooperating with this process and diligently pulling all documents requested,” CISD Executive Director of Communication Karen Fitzgerald said in a statement. “Our focus will always be what is best for our students as we prepare them for their next steps in their educational journey.”

The office, housed under the U.S. Department of Education, is tasked with ensuring "equal access to education and [promoting] educational excellence through vigorous enforcement of civil rights." According to the office’s website, a complaint of discrimination can be filed by anyone who believes that an educational institution receiving federal financial assistance has discriminated against someone on the basis of race, color, national origin, sex, disability or age.

The person or organization filing the complaint does not need to be a victim of the alleged discrimination and may complain on behalf of another person or group, according to the site.

The district received three letters, one for each complaint, on Nov. 12 from the office about its investigations. A portion of one letter shared by the district states that “opening a complaint allegation for investigation in no way implies that [the office] has made a determination with regard to its merits. During the investigation, [the office] is a neutral fact finder, collecting and analyzing relevant evidence from the complainant, the recipient and other sources as appropriate.”

CISD has been at the center of community tensions in Southlake after several videos surfaced over the last three years showing students using racial slurs. A cultural competence action plan, proposed in the aftermath to address concerns of discrimination in the district, created additional tensions, the byproduct of which led to a lawsuit against the district for violating the Texas Open Meetings Act.

On Nov. 10, CISD Superintendent Lane Ledbetter addressed the community, asking it to focus back on the district's students and staff rather than the divisions within the district. A staff training session secretly recorded and shared with NBC News last month about an administrator's comment that referenced two sides to the Holocaust prompted the district to issue an apology. On Nov. 15, board trustees were presented with a proposed policy change that would prohibit secret recordings by staff unless all parties consent.