Elon Musk’s AI startup xAI is escalating its fight with OpenAI.

Musk’s company filed a new lawsuit in the US District Court for the Northern District of California, accusing the ChatGPT creator of poaching staff and stealing confidential technology.

The complaint, filed Wednesday, claims OpenAI has engaged in a “deeply troubling pattern” of recruiting former xAI employees to gain access to trade secrets related to Grok, xAI’s flagship chatbot.

“OpenAI is not merely soliciting or hiring a competitor’s employees,” Musk lawyers wrote in the complaint. “OpenAI is waging a coordinated, unfair, and unlawful campaign: OpenAI is targeting those individuals with knowledge of xAI’s key technologies and business plans.”

The lawsuit also alleges that OpenAI has encouraged these recruits to violate confidentiality agreements with xAI.

A spokesperson for OpenAI denied the allegations.

“This new lawsuit is the latest chapter in Mr. Musk’s ongoing harassment,” OpenAI said in a statement to Business Insider. “We have no tolerance for any breaches of confidentiality, nor any interest in trade secrets from other labs.”

The lawsuit names ex-xAI engineer Xuechen Li, who is facing a separate case filed in August by xAI over alleged trade secret theft. On September 3, xAI won a court order to temporarily block Li from working on or communicating about AI technology with OpenAI.

A source with knowledge of the issue also told Business Insider that Li, the engineer in question, never worked at OpenAI.

In the filing, xAI alleged OpenAI hired away “early xAI engineer” Jimmy Fraiture and a senior finance executive in an effort to obtain xAI’s sensitive information. Fraiture is not a defendant in the complaint.

Li did not immediately respond to requests for comment.

The case adds to a widening legal war between Musk and OpenAI, the company he cofounded in 2015. XAI separately sued Apple in August, accusing it of conspiring with OpenAI to stifle competition. Musk is already pursuing claims that OpenAI betrayed its nonprofit roots by converting into a for-profit venture. OpenAI has also countersued Musk for harassment.

Attorneys for xAI did not immediately respond to a request for comment from Business Insider. Musk did not immediately respond to a request for comment.