Uber has hired former U.S. Attorney General Eric Holder to lead an investigation into a former engineer's explosive allegations of gender discrimination and sexual harassment, according to a company-wide email sent on Monday by CEO Travis Kalanick. This comes less than 24 hours after Uber board member Arianna Huffington said that she and new HR chief Liane Hornsey would lead an "independent" investigation, which some quickly noted was hardly independent.

Huffington and Hornsey both will still be involved, as will Holder's law partner Tammy Albarran and Uber associate general counsel Angela Padilla. The group also will dig into Uber's overall workplace culture as it pertains to diversity and inclusion. In that vein, Kalanick pledged that Uber in the coming months will release its first workforce diversity report, something it hasn't done despite the example set by many of Silicon Valley's other large technology companies.

Why Holder? He's a respected outsider, although he has been publicly supportive of Uber in the past, such as arguing in favor of the company's background check practices. Holder also was hired last summer by Airbnb to craft an anti-discrimination policy, so he has some Silicon Valley experience.

What's next: Uber will be closely watched as it embarks on this investigation, and especially once the results are out. With a longstanding reputation for ignoring and excusing bad behavior, there will be a lot of pressure on the company to make bold moves if Holder finds the allegations to be truthful.

Below is Kalanick's email

Team,It's been a tough 24 hours. I know the company is hurting, and understand everyone has been waiting for more information on where things stand and what actions we are going to take.

First, Eric Holder, former US Attorney General under President Obama, and Tammy Albarran -- both partners at the leading law firm Covington & Burling-- will conduct an independent review into the specific issues relating to the work place environment raised by Susan Fowler, as well as diversity and inclusion at Uber more broadly. Joining them will be Arianna Huffington, who sits on Uber's board, Liane Hornsey, our recently hired Chief Human Resources Officer, and Angela Padilla, our Associate General Counsel. I expect them to conduct this review in short order.

Second, Arianna is flying out to join me and Liane at our all hands meeting tomorrow to discuss what's happened and next steps. Arianna and Liane will also be doing smaller group and one-on-one listening sessions to get your feedback directly.

Third, there have been many questions about the gender diversity of Uber's technology teams. If you look across our engineering, product management, and scientist roles, 15.1% of employees are women and this has not changed substantively in the last year. As points of reference, Facebook is at 17%, Google at 18% and Twitter is at 10%. Liane and I will be working to publish a broader diversity report for the company in the coming months.

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. What is driving me through all this is a determination that we take what's happened as an opportunity to heal wounds of the past and set a new standard for justice in the workplace. It is my number one priority that we come through this a better organization, where we live our values and fight for and support those who experience injustice.

Thanks,Travis