OpenAI is asking Meta to produce evidence related to any coordinated plans with Elon Musk and xAI to acquire or invest in the ChatGPT-maker.

The request was made public in a brief filed Thursday in Elon Musk’s ongoing lawsuit against OpenAI. Lawyers representing OpenAI said they subpoenaed Meta in June for documents related to its potential involvement in Musk’s unsolicited $97 billion bid to take over the startup in February. It’s unclear from the filing whether such documents exist. OpenAI ultimately rejected Musk’s bid.

OpenAI’s lawyers said they discovered that Musk communicated with Meta CEO Mark Zuckerberg concerning xAI’s bid to purchase the ChatGPT-maker, including “about potential financing arrangements or investments.”

Meta objected to OpenAI’s initial subpoena in July; the ChatGPT-maker’s lawyers are now seeking a court order to obtain such evidence. OpenAI is also asking the court for any of Meta’s documents and communications related to “any actual or potential restructuring or recapitalization of OpenAI” — the core issue in Musk’s lawsuit against OpenAI.

Meta spokesperson Andy Stone directed TechCrunch to a section of OpenAI’s filing which states that neither Meta nor Zuckerberg signed Musk’s letter of intent to acquire the ChatGPT-maker.