Elon Musk’s legal team filed another notice on Tuesday to terminate his $44 billion deal to buy Twitter, citing additional reasons.

Twitter shares were down more than 1% in premarket trade.

The latest filings come after Twitter’s former head of security, Peiter “Mudge” Zatko, alleged earlier this month “extreme, egregious deficiencies” by the social media company related to privacy, security and content moderation.

On July 8, Musk’s legal team initially filed a notice with the U.S. Securities and Exchange Commission to terminate the Twitter acquisition. Musk’s team alleged that “Twitter has not complied with its contractual obligations.”

The follow-up notice, disclosed to the SEC, cites allegations made by Zatko as additional reasons to terminate the deal.

“Allegations regarding certain facts, known to Twitter prior to and as of July 8, 2022, but undisclosed to the Musk Parties prior to and at that time, have since come to light that provide additional and distinct bases to terminate the Merger Agreement,” Mike Ringler, Musk’s legal representative from Skadden, Arps, Slate, Meagher & Flom, wrote in a letter to Twitter’s legal chief.