The Education Department has opened an investigation into Smith College over the all-female institution's decision to admit males who identify as women.

The investigation opened Monday is looking into whether the policy violates Title IX, which forbids discrimination based on sex in education. 

The law contains a single-sex exception allowing all-male or all-female enrollment at an institution, but the Education Department argues this applies only to biological sex and not subjective gender identity. 

Smith College, in western Massachusetts and one of the country's prestigious Seven Sisters schools, has admitted males who identify as women since 2015, according to Politico.

"An all-women’s college loses all meaning if it is admitting biological males," said Assistant Secretary for Civil Rights Kimberly Richey. "Allowing biological males into spaces designed for women raises serious concerns about privacy, fairness, and compliance under federal law. The Trump Administration will continue to uphold the law and fight to restore common sense."