Tech giant Google Inc.'s self-driving car unit Waymo has accused Uber Technologies Inc. of using its stolen intellectual property for its own self-driving vehicles.

Waymo, which spun out of the internet giant's parent company, filed a lawsuit in a federal court in San Francisco on Thursday, claiming that the technology being used by UBER was stolen by one of its former project leaders.

The Google unit said Anthony Levandowski, who now runs Uber's self-driving car division, downloaded nearly 14,000 files from its servers around a month before leaving the company to start his own company called Otto. Later, Uber acquired Otto for $680 million.

Waymo said in the lawsuit, "Otto and Uber have taken Waymo's intellectual property so that they could avoid incurring the risk, time, and expense of independently developing their own technology. This calculated theft reportedly netted Otto employees over half a billion dollars and allowed Uber to revive a stalled program, all at Waymo's expense."

The technology in question is regarding the circuit board design for Uber's lidar (light detection and ranging) technology that is used in laser-based sensors in self-driving vehicles.

Uber, which recently expanded its self-driving program to Tempe, Arizona, didn't respond to repeated requests for a comment on the issue.