Apple has sent legal preservation letters to approximately 40 former employees now working at OpenAI, according to the Financial Times. These formal notices require recipients to preserve documents and evidence potentially relevant to Apple's lawsuit alleging trade secret theft.

The letters follow Apple's lawsuit filed last week naming OpenAI, io Products, and former Apple employees Chang Liu and Tang Tan as defendants. Apple alleges these individuals stole trade secrets "for the benefit of OpenAI," and suspects the misappropriation may extend beyond those initially named.

A preservation letter is a formal written notice specifying what records must be retained for a legal dispute. OpenAI has stated it has seen no evidence supporting Apple's trade secret theft claims. The lawsuit reveals how many former Apple employees have joined the AI company, though the hardware timeline remains unchanged.