Uber Technologies Inc’s Chief People Officer Liane Hornsey resigned in an email to staff on Tuesday, following an investigation into how she handled allegations of racial discrimination at the company, reported Reuters.

The resignation came after the news agency contacted Uber on Monday about an investigation into accusations by whistleblowers that Hornsey had systematically dismissed internal complaints of racial discrimination.

Hornsey was head of Uber’s human resources department and one of the firm’s top spokespersons on diversity and discrimination issues. She held the post for about 18 months, a period during which the company faced allegations of gender discrimination and sexual harassment. The charges eventually led to an investigation by former United States Attorney General Eric Holder last year, followed by Uber Chief Executive Officer Travis Kalanick’s resignation.

Chief Executive Officer Dara Khosrowshahi praised Hornsey in an email to employees, which was accessed by Reuters, as “incredibly talented, creative, and hard-working.” He gave no reason for her departure.

Hornsey acknowledged in a separate email to her team at Uber, also seen by Reuters, that her exit “comes a little out of the blue for some of you, but I have been thinking about this for a while.”

The allegations against her and Uber’s human resources department have been made by an anonymous group that claims to be made up of Uber employees of colour, Reuters reported quoting members of the group.

They alleged Hornsey had used discriminatory language and made derogatory comments about Uber Global Head of Diversity and Inclusion Bernard Coleman, and had threatened former Uber executive Bozoma Saint John, who left the company in June.

Investigation into sexual harassment, sexism at Uber

The investigation began after a former employee alleged sexual harassment and sexism at the company in a blogpost in February 2017. The woman, who had worked for Uber between November 2015 and December 2016, also alleged that the company’s human resources department did not act on her accusations.

In June 2017, Uber fired its Asia-Pacific business head Eric Alexander after it was found that he had made copies of and shared the medical records of a woman who had been raped while using the company’s taxi service in Delhi in 2014. He is believed to have shown the medical records to Kalanick and Uber Senior Vice President Emil Michael.