Meta has been asked by OpenAI to provide evidence of any collaboration with Elon Musk and xAI regarding an attempt to acquire or invest in the ChatGPT-maker, according to newly released court records.

The subpoena was disclosed Thursday in a filing related to Musk’s lawsuit against OpenAI. Lawyers for the company said Meta was served in June for documents about Musk’s unsolicited $97 billion takeover bid earlier this year. It is uncertain whether the requested documents exist, and OpenAI ultimately rejected the offer.

The broader case involves Musk’s opposition to OpenAI’s restructuring into a public benefit corporation, which the company says is necessary to attract investment and prepare for a public market debut. Musk argues that the change contradicts the company’s founding principles.

Meta’s attorneys have asked the court to block the subpoena, maintaining that Musk and xAI are the appropriate sources for relevant information. They also assert that Meta’s internal deliberations over OpenAI’s restructuring are not relevant.