Apple hasn't confirmed what its plans are for a self-driving car, but that hasn't prevented the company from trying to stop ex-employees from walking off with its trade secrets.

In a filing with the U.S. District Court for the Northern District of California on Monday, Apple said that it has "deep concerns" that two of its former employees, ​Xiaolang Zhang and Jizhong Chen, could try to flee to China with files on Apple's Project Titan self-driving car initiative rather than face trial. Apple asked that the court monitor the defendants ahead of their trial, according to Reuters.

Both Zhang and Chen were charged with one count of criminal trade secrets theft. Zhang is alleged to have taken files related to Project Titan and was going to work for a Chinese competitor before he was stopped at the San Jose airport by federal agents as he was about to board a flight for China.

Chen, meanwhile, is alleged to have stolen 2,000 Project Titan files, including "manuals, schematics, diagrams," and other content. Chen was arrested en route to the San Francisco airport to board a flight to China.

While both men pleaded not guilty to the charges, Apple still fears that they're a flight risk. And if they have access to files related to Project Titan, it's possible, Apple argues, that such information could fall into competitors' hands.

Seeing Project Titan documents leaked to China is a legitimate concern for Apple. The company has spent billions of dollars and many years testing its self-driving car technology.

Initially, there had been reports that Apple would build its own car, but over time, the company reportedly abandoned those plans and has focused on self-driving car technology that it would sell to automakers.

For its part, Apple has been silent on its plans, despite obtaining dozens of DMV licenses to operate self-driving cars on California roads. When pressed on what Apple might do in the car business, the company has had little, if anything, to say.

Still, the threat of losing technology to China is a very real one for Apple and other prominent technology companies. China has been criticized for allowing companues to steal intellectual property from American organizations. Seeing a technology that hasn't launched yet and costs billions be used in a competing product could derail plans Apple has for Project Titan--especially in China, where it might want to capitalize on a massive market.

But alas, both Zhang and Chen have said they're not guilty. And it's worth noting that both Apple and the U.S. government have said they shouldn't be detained. Instead, they believe the ex-Apple employees should be monitored to ensure they don't go to China.

The trial dates for Zhang and Chen haven't been set, but federal prosecutors expect to try the cases sometime in 2020.