In response to claims about sexual harassment at Uber made by a former employee over the weekend, the ride-hailing company announced Monday it had hired former U.S. Attorney General Eric Holder to probe the allegations. 

Huffington Post’s co-founder Ariana Huffington, who joined Uber’s board of directors last year, will join Holder in the investigation. The two will be accompanied by the company’s human resources chief Liane Hornsey and Uber’s associate general counsel Angela Padilla, CEO Travis Kalanick said in a memo to his staff.

Holder served as attorney general in former President Barack Obama's administration between 2009 and 2015. He rejoined Covington & Burling — the law firm he worked with prior to his stint as the attorney general — in July 2015, and last year, he was tapped in to investigate Airbnb's anti-discrimination policy.

In his memo, Kalanick also addressed the issue of gender diversity, something that Susan J. Fowler — the former Uber engineer who made the sexual harassment allegations — said was lacking in the company. 

“If you look across our engineering, product management, and scientist roles, 15.1 percent of employees are women and this has not changed substantively in the last year. … I believe in creating a workplace where a deep sense of justice underpins everything we do. Every Uber employee should be proud of the culture we have and what we will build together over time,” the CEO wrote.

The memo came just a day after Fowler wrote a blog post alleging that Uber did not take action on complaints about her boss soliciting her for sex.

“On my first official day rotating on the team, my new manager sent me a string of messages over company chat. … It was clear that he was trying to get me to have sex with him, and it was so clearly out of line that I immediately took screenshots of these chat messages and reported him to HR,” Fowler wrote in the post.

The management told Fowler that the company “wouldn’t feel comfortable giving him anything other than a warning and a stern talking-to” because it was the manager’s “first offense,” the post read. She was reportedly told that “no further action could or would be taken.” After transferring teams, Fowler found that many other female employees had faced similar harassment during their tenure at Uber.