Originally Published: 29 AUG 22 12:23 ET

Updated: 29 AUG 22 17:11 ET

By Clare Duffy, CNN Business

(CNN) -- Elon Musk's legal team has subpoenaed former Twitter head of security and whistleblower Peiter "Mudge" Zatko to appear for a deposition in its legal fight against Twitter over their acquisition deal on September 9.

The subpoena, which was sent Thursday and filed publicly on Monday, comes days after Zatko publicly blew the whistle on the social media company, alleging that it has serious privacy and security vulnerabilities that could put users, investors and US national security at risk. The disclosure's timing is fortuitous for Musk, who is fighting a lawsuit from Twitter that seeks to compel him to follow through with his $44 billion deal to buy the company, after he attempted to terminate the agreement over claims that Twitter has more spam and fake bot accounts than it publicly discloses. The case is set to go to trial in October.

In the disclosure, Zatko claimed that Twitter does not have an accurate count of the number of spam and fake bot accounts on its platform and that the company has little incentive to undertake a full count of such accounts, allegations that could potentially burnish Musk's claims. Twitter has criticized Zatko and broadly pushed back on his allegations, saying the disclosure paints a "false narrative" of the company and is "riddled with inconsistencies and inaccuracies."

Musk lawyer Alex Spiro told CNN last week that they had subpoenaed Zatko in the case even before his whistleblower complaint was made public. In a court hearing in the case last Wednesday, Spiro mentioned Zatko multiple times. Spiro suggested during the hearing that the billionaire's team does not trust Twitter's estimate for spam accounts and monetizable daily active users (mDAU), a key metric it provides to investors, and said Musk's team is requesting information that would allow them to test the measurements.

The new subpoena is yet another indication of how Zatko's claims could impact the case. In addition to the deposition, Musk's team also demanded in the Thursday subpoena "books, documents, or tangible things in your possession" related to Twitter's counting of spam and false accounts and its use of mDAU as a key metric.

"Mr. Zatko will comply with his legal obligations of that subpoena and his appearance at the deposition is involuntary," Zatko's attorneys, Debra Katz and Alexis Ronickher, said in a statement Monday. "He did not make his whistleblower disclosures to the appropriate governmental bodies to benefit Musk or to harm Twitter, but rather to protect the American public and Twitter shareholders."

Zatko is also set to testify about his allegations at a Senate Judiciary Committee hearing on September 13.