Zee.Aero, which set up shop next to Google HQ in Mountain View, California back in 2010, has previously denied any affiliation with Google -- or any tech company for that matter -- but has reportedly been funded in secret by Page since its inception.
Page is said to have spent more than $100 million of his personal fortune on the company, but demanded his involvement be kept hidden from the public, said Bloomberg, citing 10 people with intimate knowledge of Zee.Aero.
The company is said to be building an electric plane that can take off and land vertically, with the help of aerospace designers and engineers hired from NASA, Boeing and Space X.
The second startup, Kitty Hawk, is reported by Bloomberg to be building a vehicle "that resembles a giant version of a quadcopter drone." Page supposedly invested in the company, which is headed up by founder of the Google X special projects research division, last year.
Google and Zee.Aero did not immediately respond to requests for comment. Kitty Hawk could not be reached.
This article originally appeared on CNET.com.