Apple has filed what it describes as shocking evidence in its trade secrets lawsuit against OpenAI, alleging that a former employee used confidential Apple circuit schematics in his work at OpenAI and then enlisted a colleague to destroy evidence when he learned he was under investigation.

The new filing centres on Chang Liu, a former Apple employee who now works at OpenAI. Apple says that after Liu's old work laptop was handed over for examination earlier this month, analysis confirmed he had used a confidential Apple circuit schematic at OpenAI, along with a software tool sharing the name of an internal Apple engineering application. The company alleges that OpenAI was fully aware of Liu's continued access to Apple data.

Apple further claims that in June, upon discovering he was being investigated, Liu enlisted OpenAI colleague Yu-Ting Peng to help destroy evidence of the theft. "Apple is not conducting fishing expeditions but that its trade secrets are being used and evidence is being destroyed," the filing states.

OpenAI has previously said Liu only accessed Apple files after leaving in order to help former colleagues who had asked for his assistance, arguing the situation reflects Apple's own failure to properly manage system access when employees depart. Apple says Liu maintained access by exploiting a rare authentication bug.

Apple is seeking a preliminary injunction to block OpenAI from working on hardware based on its technology. More than 400 former Apple employees now work at OpenAI, according to Apple's initial filing.