A former Uber exec says that half of Uber's staff may have been hired in the last 6 months

A former Uber executive has revealed what he believes to be the extent of Uber's hiring spree this year.

Six-year-old Uber is now thought to have 4,000 employees globally, excluding drivers.

More than 2,000 of those could have been hired in the last six months, according to Lars Fjeldsoe-Nielsen, ex-VP of Mobile at Uber.

"I wouldn't be surprised if over 50% of Uber employees have been hired in the last six months," he said during an interview with Business Insider at Balderton Capital's office in London, where he now works as a venture capitalist. "I wouldn't be surprised at all."

Fjeldsoe-Nielsen was keen to stress that he wasn't sure on the exact figures and that he was purely guessing.

He added that he believes the growth of Uber's workforce isn't directly linked to the company's latest funding rounds.

"It's more the growth of the service," he said. "The funding numbers are so big so if Uber is raising $2 billion (£1.35 billion) now, I'm not really sure how much that's going to change hiring."

Uber now operates in 351 cities in 64 countries and has over 1.1 million active driver-partners, according to The Guardian.

Fjeldsoe-Nielsen has got some good experience with fast growing companies. Prior to joining Uber, he worked at Dropbox and advised WhatsApp on business development matters. He also appears to have a relatively good understanding of the growth of Facebook and Google, which employ 11,996 and 59,976 respectively.

"I think Facebook probably had a period of time where they went through the same [growth as Uber]. Dropbox certainly did. But WhatsApp is very different. It stayed very small, despite them having such a massive user based. The ratio of engineers to users is unheard of. Probably even more than Google actually."

Uber is yet to comment.