At the Sunday meeting, the company's board adopted a series of recommendations from the law firm of former US Attorney General Eric Holder following a multi-month investigation into Uber's culture and practices.

The company is also adding a new independent director, Nestle executive and Alibaba board member Wan Ling Martello, a company spokesman said.

Uber hired Holder in February to investigate company practices after former Uber engineer Susan Fowler published a blog post detailing what she described as sexual harassment and a lack of a suitable response by senior managers.

Holder recommended greater controls on spending, human resources and other areas where executives led by Kalanick had too much freedom for a company with more than 12,000 employees.

Kalanick and two allies on the board have voting control of the company. Kalanick's forceful personality and enormous success with Uber to date, as well as his super-voting shares, have won him broad deference in the boardroom.

Any decision to take a leave of absence will ultimately be Kalanick's but it seems that he might have met his Waterloo. His approach has led to a number of complaints from employees and drivers.

It is facing a criminal probe by the US Department of Justice over its use of a software tool that helped its drivers evade local transportation regulators.

Uber fired 20 staff after another law firm looked into 215 cases encompassing complaints of sexual harassment, discrimination, unprofessional behaviour, bullying and other employee claims.

Uber board member Arianna Huffington said in March that Kalanick needed to change his leadership style from that of a "scrappy entrepreneur" to be more like a "leader of a major global company."

The board has been looking for a chief operating officer to help Kalanick with his homework and perhaps press the button which sends a small amount of voltage to his testicles whenever he starts to misbehave (we made that last bit up).

But Kalanick might not particularly care about work right now anyway. His mum was killed and his dad was badly injured in a boating accident last month, so disappearing for a while might be a good idea.