Apple has expanded its legal battle with OpenAI with reports that it has sent legal preservation letters to around 40 former employees who now work at OpenAI. The company is investigating allegations that confidential Apple technology information was improperly obtained.

The letters instruct recipients to preserve potentially relevant documents, communications and other evidence that could be used in the ongoing dispute. While the former employees have not been named as defendants, the move signals that Apple believes the alleged misuse of confidential information may extend beyond the individuals already targeted in its lawsuit.

Apple has recently sued OpenAI, along with former Apple executives including Tang Tan, who now leads OpenAI’s hardware efforts, and former Apple engineer Chang Liu, accusing them of misappropriating trade secrets linked to hardware development and future products.

The dispute centres on Apple’s claim that confidential information covering areas such as hardware engineering, manufacturing processes and unreleased product plans may have been used to speed up OpenAI’s move into consumer hardware. Apple has described the evidence uncovered so far as potentially only the “tip of the iceberg”. 

Following its acquisition of AI hardware startup io, OpenAI is reportedly pushing deeper into hardware, with plans to develop new consumer devices that could compete with Apple and other major tech companies.

Apple’s lawsuit claims that the movement of talent between Apple and OpenAI raises concerns about the protection of intellectual property in the AI era. 

According to Apple, more than 400 former Apple employees are reportedly now working at OpenAI. The company has not alleged that all former employees were involved in any wrongdoing.

OpenAI has rejected Apple’s allegations, saying it is not aware of evidence supporting the claims.

For the technology industry, the dispute highlights a growing challenge for companies to protect trade secrets as AI companies aggressively recruit experienced engineers. 

The case also raises questions around intellectual property, and the ownership or knowledge and expertise, as employees move between competing companies, particularly in the fast-growing fields of AI and connected hardware.