Tesla Inc. and Apple Inc. both suspect they were betrayed by driverless technology engineers who defected to the same Chinese startup.

So Tesla is now asking for Apple's help in a lawsuit in which the electric carmaker accused an engineer who worked on its Autopilot program of taking thousands of highly confidential files when he went to work for XMotors.ai, the U.S. research arm of Guangzhou-based Xpeng.

Along with typical information demands in the early fact-finding phase of the lawsuit that are spelled out in a court filing last week — Tesla wants to see the engineer's emails and have a forensic analysis conducted on his electronic devices — the company founded by Elon Musk disclosed that it has also served the iPhone maker with a subpoena.