The Asian American Coalition for Education first filed a complaint against Yale, Brown University, and Dartmouth College in 2016, alleging the institutions “participate in a covert and insidious scheme” to limit Asian American admittance to enforce race-based quotas.

According to The Washington Post, the Education Department’s Office for Civil Rights sent a letter concerning the investigation to the coalition on Wednesday, announcing a probe into Yale admissions was opened in April of this year. The office is not investigating Brown and Dartmouth, citing a lack of detail.

Yale’s leadership has denied the allegations: in a letter to the university community, President Peter Salovey stated, “Yale does not discriminate in admissions against Asian Americans or any other racial or ethnic group.”

“We take into consideration a multitude of factors,” the president continued, “including their academic achievement, interests, demonstrated leadership, background, success in taking maximum advantage of their secondary school and community resources, and the likelihood that they will contribute to the Yale community and the world. This whole-person approach to admissions complies fully with all legal requirements and has been endorsed repeatedly by the Supreme Court.”

While Title VI of the Civil Rights Act prohibit schools from discriminating on the basis of race, color or national origin, a 2016 Supreme Court decision upholding affirmative action practices at a Texas university stated race could be used as one factor among many when determining applicants’ admittance, for the sake of student diversity.

Under the Trump administration, however, the Department of Education returned to Bush-era regulations encouraging “race-neutral methods” of student acceptance. The move permitted investigations like the ones against Yale and Harvard, which is also accused of discriminating against Asian Americans.