SAN JOSE, CALIFORNIA (NYTIMES) - Anthony Levandowski was once one of Silicon Valley's most sought-after technologists.

As a pioneer of self-driving car technology, he became a confidant of Mr Larry Page, a co-founder of Google, and helped develop the search giant's autonomous vehicles. Uber wooed him to gain an edge in self-driving techniques.

But on Tuesday (Aug 27), Levandowski, 39, fell far from that favoured stature. Federal prosecutors charged him with 33 counts of theft and attempted theft of trade secrets from Google. At an arraignment in a federal courthouse in San Jose, California, Levandowski posted a US$2 million (S$2.7 million) bail and was ordered to wear an ankle monitor after prosecutors argued he was a flight risk.

The criminal indictment against Levandowski from the US Attorney's Office for the Northern District of California opens a new chapter in a legal battle that has embroiled Google, its self-driving car spin-off Waymo and its rival Uber in the high-stakes contest over autonomous vehicles.

According to the indictment, Levandowski downloaded more than 14,000 files containing critical information about Google's autonomous-vehicle research before leaving the company in 2016. He then made an unauthorised transfer of the files to his personal laptop, the indictment said. Levandowski joined Uber later that year when the ride-hailing firm bought his new self-driving trucking start-up.

Some of the files that Levandowski took from Google included private schematics for proprietary circuit boards and designs for light sensor technology, known as Lidar, which are used in self-driving cars, according to the indictment.

The US Attorney's Office said the indictment was returned by a federal grand jury on Aug 15 and unsealed on Tuesday. Levandowski turned himself in at the federal courthouse in San Jose on Tuesday morning. At his arraignment, he pleaded not guilty to all charges.

Levandowski's next court date is Sept 4. If he is convicted, he could face a maximum of 10 years in prison, a US$250,000 fine for every count and additional restitution.

One of Levandowski's lawyers, Mr Miles Erlich, said: "For more than a decade, Anthony Levandowski has been an industry-leading innovator in the field of self-driving car and truck technology. And the evidence in this case is going to show conclusively that Anthony did not steal anything."

Ms Suzanne Philion, a spokesman for Waymo, said it had "always believed competition should be fuelled by innovation and we appreciate the work of the US Attorney's Office and the FBI on this case".