Hong Kong (CNN Business) The FBI is accusing a Chinese national of stealing trade secrets while working for Apple.

Apple's AAPL It alleges that engineer Jizhong Chen attempted to take key details fromsecretive self-driving car project. Chen was arrested and charged last week, just before he was scheduled to fly to China, according to a criminal complaint filed in US district court in California.

Apple said that if the confidential material got out, it would be "enormously damaging" for the company, the complaint said.

It's the second time in about six months that a Chinese national has been charged with stealing secrets from the Apple project, whose existence the company refuses to even acknowledge publicly.

Read More