The Senate Judiciary Committee will hold a hearing on Sept. 13 with Twitter’s former security chief Peiter “Mudge” Zatko to discuss allegations from his whistleblower complaint that the social media company misled regulators.

Zatko, who accused Twitter of falsely claiming it had a solid security plan and making misleading statements about its defenses against hackers and spam accounts, has already discussed his complaint with staff in the office of Sen. Richard Blumenthal this week, said two sources familiar with the situation.

In an 84-page complaint Zatko, a famed hacker widely known as “Mudge,” made numerous claims and alleged Twitter prioritized user growth over reducing spam, with executives eligible to win individual bonuses of as much as $10 million tied to increases in daily users, and nothing explicitly for cutting spam, according to documents relayed by congressional investigators. 

Twitter has labeled the complaint a “false narrative.” 

“The Senate Judiciary Committee will investigate this issue further with a full committee hearing this work period, and take further steps as needed to get to the bottom of these alarming allegations,” said committee chair Sen. Richard Durbin and top Republican member Sen. Chuck Grassley.

Blumenthal, a Democrat on the Senate Commerce Committee and the Judiciary Committee with a keen interest in Big Tech, wrote in a letter to Federal Trade Commission chair Lina Khan: “According to disclosures and evidence provided by Peiter ‘Mudge’ Zatko, a highly-respected cybersecurity expert who served as Twitter’s Security Lead from 2020 to 2022, Twitter executives allegedly failed to address significant security vulnerabilities, neglected the mishandling of personal data, and ignored known privacy risks to users for more than a decade.”

Blumenthal called for an FTC investigation in the letter.