MILWAUKEE (AP) — The brother of former first lady Michelle Obama and his wife are suing a private Milwaukee school alleging it refused to allow their two young sons to re-enroll after they voiced concerns that racism and inappropriate conduct at the school was not addressed.

In a civil lawsuit filed in Milwaukee County Circuit Court, Craig and Kelly Robinson accuse University School of Milwaukee officials of terminating their 9- and 11-year-old sons’ re-enrollment contracts for the 2021-2022 school year after the couple complained that teachers treated students of color and socioeconomically underrepresented students unfairly.

USM said in a statement that the enrollment decision had nothing to do with their complaints of inequity or discrimination.