Reuters reached out to Uber on Monday about a previously unreported investigation into accusations that Uber’s head of human resources, Liane Hornsey, systematically dismissed internal complaints of racial discrimination. Hornsey has since stepped down via an email to the staff.

Hornsey has been in her position for around 18 months, a period of time that saw controversies such as former software engineer Susan Fowler publishing a blog about the sexual harassment she faced while employed by the company. A few months later, co-founder Travis Kalanick resigned from his position of CEO after accusations were made that Uber fosters a hostile work environment.

An anonymous group claiming to be employees of color at Uber made allegations against Hornsey and the Uber human resources department. There was allegedly an email to Chief Legal Officer Tony West and Uber’s whistle-blower account threatening to be open about Hornsey dismissing internal reports of racial discrimination if action wasn’t taken, according to Fortune.

Some other accusations state that Hornsey used discriminatory language and derogatory comments about employees. According to Reuters, some of the allegations were indeed substantiated and investigators were wrapping up another investigation after receiving another similar complaint.

CEO Dara Khosrowshahi was the first to announce Hornsey’s resignation in an email to staff. In a later email she sent out following the CEOs, Hornsey implied that she had been thinking about departing the company for “a while.”

Hornsey gave no reason for her departure, and neither did CEO Khosrowshahi.