Elon Musk and Twitter are now fighting about Signal messages

Elon Musk’s private messages could once again land him in hot water in his legal fight with Twitter. Lawyers for the two sides once again faced off in Delaware’s Court of Chancery ahead of an October trial that will determine the fate of the deal.

Among the issues raised in the more than three-hour long hearing was Musk’s use of encrypted messaging app Signal. Twitter’s lawyers claim that Musk has been withholding messages sent via the app, citing a screenshot of an exchange between Musk and Jared Birchall, the head of Musk’s family office.

According to Twitter’s lawyers, the message referenced Morgan Stanley and Marc Andreesen as well as “a conversation about EU regulatory approval” of Musk’s deal with Twitter. Twitter’s lawyers said they uncovered a screenshot of the exchange after Musk and Birchall had denied using Signal to talk about the deal. The screenshot showed the message was set to automatically delete.

Lawyers for Twitter also cited “a missing text message” between Musk and Oracle Chairman , who was set to be a co-investor in the Twitter deal. Musk and Ellison were texting the morning before Musk that the Twitter deal was “temporarily on hold.” It’s not clear what the significance of the texts are, but Twitter’s lawyers noted that Musk wrote to Ellison saying “interesting times” before arranging a phone call with him.

Twitter’s lawyers are asking the judge in the case, Kathaleen St. J. McCormick, to sanction Musk over his side’s handling of his messages. “We do think that the time has come for the court to issue a severe sanction,” Twitter’s lawyers said during the hearing.

Musk’s side attempted to downplay the significance of the Tesla CEO’s use of Signal. “There actually is no evidence that we destroyed evidence,” one of Musk’s lawyers responded. “Signal, you know, it sounds like it’s a nefarious device,” she said. “In fact, Twitter executives have testified that a number of them actually use Signal messaging.”

Musk’s lawyers cited the existence of Signal messages between Jack Dorsey and board chair Bret Taylor, and noted that current CEO Parag Agrawal has also turned over Signal messages. “Signal is not some exotic mechanism, it’s very common in Silicon Valley to use this platform,” she said.

Notably, the latest hearing is not the first time Twitter’s lawyers have used Musk’s private messages obtained in the legal discovery process in their bid to enforce the original terms of the deal with Musk. Twitter’s lawyers previously called out a text message between Musk and one of his Morgan Stanley bankers in which he cited concerns about as a reason to slow-roll his negotiations with Twitter.

McCormick is expected to rule on Twitter’s motion to sanction Musk in the next couple days. A five-day trial that will determine the fate of the deal is scheduled for .