China’s vision of profiting from the driverless economy is being clouded by intellectual property debates, as two Chinese suppliers of a key self-driving technology are accused of stealing IP from a Silicon Valley company.

Velodyne, the world’s largest producer of lidar—a radar-like sensor technology that uses lasers instead of radio waves—has brought patent infringement complaints against Suteng (also known as Robosense) and Hesai. According to two complaints filed to the United States District Court for the Northern District of California on Tuesday (Aug. 13), San Jose-based Velodyne said the two Chinese companies have “threatened Velodyne and its business” by copying its flagship technology: lidar configurations that allow vehicles to “see” their surroundings by bouncing lasers off objects.

The majority of self-driving companies rely on lidar: Silicon Valley’s Waymo, Chinese search giant Baidu, China’s state-owned electric vehicle maker BJEV, and autonomous driving startups Pony.ai and WeRide have all been using the technology. Usually mounted on top of the car, a lidar channel continuously sends out laser beams; as it senses the light bouncing back, it produces a 360-degree real-time map that the car uses to make decisions. Most serious players in the autonomous race see laser vision as indispensable. (Elon Musk, though, has argued that lidar isn’t necessary, and is instead banking on cameras.)

The units are incredibly expensive. A Velodyne 64-channel unit costs $85,000, more than a Tesla Model X in the US. And the more channels a lidar unit has, the more expensive it gets. A car that requires no human intervention at all—a level 5 car, at the top of the Society of Automotive Engineers’ self-driving classification scale—could require a 128-channel lidar system.

In its complaints, Velodyne said both Robosense and Hesai have been selling products that infringe on multiple aspects of US Patent No. 7,969,558 (“High Definition Lidar System“), which was awarded to Velodyne’s founder David Hall in 2011. Hall didn’t invent lidar itself, but he created the so-called “3-D point cloud” system, building upon lidar that used a single, fixed line of sight. Hall’s invention has made Velodyne’s lidar the standard for self-driving technology.

Velodyne said information it gathered has shown alleged infringement. It pointed out the similarities between its product structures and data capture technologies and those marketed by Robosense and Hesai. The complaints are identical. Here’s the one filed against Robosense:

On information and belief, Robosense copied Velodyne’s products, including the VLP-16, and learned of the ’558 patent no later than the time at which it first inspected and performed a tear-down of Velodyne’s products. And Robosense actively promotes the sale, use, and importation of its infringing rotating 3-D LiDAR devices in marketing materials, technical specifications, data sheets, web pages on its website, press releases, and user manuals, as well as at trade shows and through its sales and distribution channels that encourage infringing offers to sell, sales, and/or importation of the Accused Products. These actions collectively demonstrate that Robosense has had the specific intent to induce, or was willfully blind to inducing, infringement of the ’558 patent.

Screengrab Lidar products offered by Robosense.

Velodyne has asked the court to stop both Hesai and Robosense from selling the alleged copied products, which include all the major lidar products listed on the Chinese companies’ sites. Hesai didn’t respond to multiple calls and messages requesting comment.

In a statement to Quartz, Robosense said Velodyne is only targeting at “a few items” sold in the US. The lawsuit won’t affect the company’s sales plan globally. “Suteng will persist with researching and developing core technology,” said the statement.

WeRide, a Guangzhou-based self-driving company which also has a Silicon Valley office, has been using both Velodyne and Hesai’s lidar, said it’s refraining from commenting on the complaints, but said its road tests aren’t affected.

It’s not the first time a Chinese company has been accused of stealing driverless IP from a US company. A former Tesla self-driving engineer admitted last month he had uploaded files containing Tesla’s Autopilot source code to iCloud while he was an employee there—right around the time he took an offer from five-year-old Chinese electric car maker Xiaopeng Motors. Xiaopeng said it wasn’t aware of the engineer’s alleged misconduct. Earlier, another engineer who took a post with Xiaopeng in its Mountain View office was charged by the FBI with stealing IP from Apple’s self-driving team.

Update: The article was amended to include comment from Robosense.