Washington, Feb 21: Former US attorney general Eric Holder and Tammy Albarran -- both partners at law firm Covington and Burling -- will lead the probe into claims of sexual harassment by a former Uber employee.

Uber boss Travis Kalanick on Monday sent an email to his employees with more information about the investigation, and further plans the company has to address the issue, BBC reported.

"It's been a tough 24 hours," Kalanick said in the mail, adding the company was "hurting".

Uber on Sunday announced to conduct the investigation following a scathing blog post by Susan Fowler, who made public allegations of sexism and harassment at the company.

Holder served under former President Barack Obama between 2009 and 2015.

Arianna Huffington, the founder of the Huffington Post, will also help conduct the review. Huffington has been on Uber's board since April last year.

Also conducting the review will be Uber's new head of human resources, Liane Hornsey, and Angela Padilla, the company's associate general counsel.

After coming into widespread criticism for never having published statistics on diversity at the company, Kalanick said he would deliver figures in the "coming months".

He said that of the employees working as engineers, product managers or data scientists, 15.1 per cent were women -- a number which he said had not changed significantly in the past year.

"As points of reference, Facebook is at 17 per cent, Google at 18 per cent and Twitter at 10 per cent," the Uber boss said.

Until now, Uber had been standing firm on not publishing its diversity figures.

Most major technology companies make public their EEO-1 -- a government filing that breaks down employees by race, religion, gender and other factors.

Uber has not specified if it will publish its entire EEO-1 or just post select figures from the company.

Fowler in her blog post cited anecdotal figures of women leaving the company in droves.

Speaking specifically about the site reliability engineering team, which she worked on for a year, Fowler said that by the time she left, "out of over 150 engineers in the SRE teams, only three per cent were women".

She now works at San Francisco-based payment firm Stripe.

Uber said it would hold an "all hands" meeting on Tuesday to tell its employees what its "next steps" will be.

Former US law chief leads Uber probe over harassment claims