Lawyers representing Elon Musk in his battle with Twitter have subpoenaed former CEO Jack Dorsey. The filing is the latest development as Musk and Twitter prepare for the October trial over Musk’s attempt to bail on his $44 billion deal to buy the company.

It’s not yet clear how Dorsey factors in to Musk’s legal strategy. As noted by the Chancery Daily Twitter account, the subpoena refers to “documents and communications reflecting, referring to, or relating to the impact or effect of false or spam accounts on Twitter’s business operations.” It also references documents related to how Twitter uses mDAU or monetizable daily active users as a “key metric.” Interestingly, it also requests “documents relating to incorporating mDAU into executive or director compensation.”

Dorsey isn’t the only former Twitter executive subpoenaed by Musk. Twitter’s recently ousted product chief Kayvon Beykpour and former head of revenue Bruce Falck have also received subpoenas.

Musk has claimed that Twitter has misled him and the public about the number of bots and fake accounts on the platform. Twitter’s lawyers have argued that Musk has repeatedly broken the terms of his agreement with the company. A five-day trial is scheduled to begin October 17th.

Dorsey previously endorsed Musk’s bid to buy Twitter, saying that “Elon is the singular solution I trust,” and that he was ““getting the company out of an impossible situation.” Dorsey hasn’t publicly weighed in on the ongoing legal battle or Musk’s claims about bots and fake accounts.