Levandowski is at the nexus of a battle between what is now Alphabet 's self-driving car company, Waymo , and ride-hailing start-up Uber. Waymo alleges that Levandowski stole thousands of documents and trade secrets for Otto, which went on to be rapidly acquired by Uber. ( Uber calls these claims "baseless." )

Levandowski was already trying to staff up his competing start-up, Otto, while he worked at Google — but he waited until he got his payout to make the details of Otto public, a lawsuit said.

Embattled engineer Anthony Levandowski collected $120 million from Google, despite involvement with at least one start-up that would ultimately compete with the company, according to new legal filings.

New court documents allege that Levandowski's conflicts of interest may have been much deeper. Not only did Levandowski try to poach Google employees, the lawsuit said, but he may have been involved in competing side businesses called Odin Wave and Tyto Lidar.

Levandowski denied having ownership interested in Odin Wave when questioned in mid-2013, the lawsuit said, and also helped Google do due diligence for a potential acquisition of Tyto — a company that Otto later acquired.

"Throughout this process, Levandowski never disclosed a relationship with Tyto and its employees," the lawsuit said. "Google now believes that Levandowski in fact had a relationship with Tyto and its employees that conflicted with Levandowski's duties to Google."

Levandowski hasn't been the only engineer to get hefty sums from Waymo . In the suit, Google said it has had to provide incentives" to convince numerous other employees not to follow Levandowski to Uber. Uber and Waymo did not immediately respond to requests for comment.

Bloomberg has previously reported that high paychecks prompted attrition at Google's car project. Bloomberg also reported that Levandowski had a long history of side projects during his time at Google, many sanctioned by founders Larry Page and Sergey Brin.

"Anthony is a rogue force of nature," former Google self-driving car executive told Bloomberg. "Each phase of his Google career he had a separate company doing exactly the same work."

Levandowski has invoked his Fifth Amendment right to avoid self-incrimination in the lawsuit, according to a transcript obtained by The New York Times. Lawyers for Levandowski could no immediately be reached.

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