WASHINGTON (AP) — A former head of security at Twitter has filed whistleblower complaints with U.S. officials, alleging that the company misled regulators about its cybersecurity defenses and its problems with fake accounts, according to reports by The Washington Post and CNN.

Peiter Zatko, Twitter’s security chief until he was fired early this year, filed the complaints last month with the U.S. Securities and Exchange Commission, the Federal Trade Commission and the Department of Justice.

The Post, which obtained the complaint, reported that among the most serious accusations is that Twitter violated the terms of a 2010 FTC settlement by falsely claiming that it had a strong security plan.

Zatko didn’t immediately respond to a request for comment Tuesday but told the Post he “felt ethically bound” to come forward.

Twitter said in a prepared statement Tuesday that Zatko was fired for “ineffective leadership and poor performance” and that the “allegations and opportunistic timing appear designed to capture attention and inflict harm on Twitter, its customers and its shareholders.”

“What we’ve seen so far is a false narrative about Twitter and our privacy and data security practices that is riddled with inconsistencies and inaccuracies and lacks important context,” the company said.

A spokesperson for the U.S. Senate’s intelligence committee, Rachel Cohen, said the committee has received the complaint and “is in the process of setting up a meeting to discuss the allegations in further detail. We take this matter seriously.”