Alphabet CEO Larry Page. Getty Images/Justin Sullivan

Former Google engineer Anthony Levandowski allegedly worked with Alphabet (Google's parent company) CEO Larry Page on flying cars in one of Page's startups, The Wall Street Journal reports.

Levandowski was one of Google's top engineers who worked on the company's self-driving car technology, and was accused by Google of stealing sensitive, classified information he allegedly brought with him to Uber through the acquisition of Ottomotto, the startup he founded immediately after leaving the search giant.

According to the WSJ report, months before his departure, Levandowski was working on a flying car project at Kitty Hawk, one of Larry Page's privately owned startups. He wasn't a formal Kitty Hawk employee, apparently, but he was allegedly testing prototype aircrafts with Page at one point.

One of Kitty Hawk's drone-like aircraft prototypes. Kitty Hawk

In the ongoing litigation between Google and Uber, which involves Page and Levandowski, Google's cofounder claimed that he tried to ward off Levandowski when it came to opening new businesses, especially if they were competing with his own work at Google.

Levandowski was highly regarded among Google's top executives, the Journal says, and worked on side projects outside of the company. However, when Levandowski declared his interest in self-driving trucks — which were technically not part of his work at Google — this didn't sit well with Page.

"I told him very, very clearly that I thought that was highly competitive and not a good idea," said Page, according to the transcript of his deposition, released last Wednesday. "I'm like, 'No, that’s not fine. Like, that's the same thing as what you're doing here. I mean, you can do that, but we are not going to be happy.'"

Google did not immediately respond to Business Insider's request for comment.