“We are engaged in a high-stakes AI arms race against China. And during my time at Meta, company executives lied about what they were doing with the Chinese Communist Party to employees, shareholders, Congress, and the American public,” Wynn-Williams said in her prepared testimony.

Her book “Careless People,” an explosive insider account of her time at the social media giant, sold 60,000 copies in its first week and reached the top 10 on Amazon.com’s best-seller list amid efforts by Meta to discredit the work and stop her from talking about her experiences at the company. Meta used a “campaign of threats and intimidation” to silence the former executive, said Sen. Richard Blumenthal, a Democrat from Connecticut, during the hearing.

Wynn-Williams served as director of global public policy at Facebook, now Meta, from 2011 until she was fired in 2017.

“Throughout those seven years, I saw Meta executives repeatedly undermine U.S. national security and betray American values. They did these things in secret to win favor with Beijing and build an $18 billion dollar business in China,” she said in her prepared remarks.

Wynn-Williams also said Meta deleted the Facebook account of a prominent Chinese dissident living in the U.S., bowing to pressure from China to do so.

In a statement, Meta said Wynn-Williams’ testimony “is divorced from reality and riddled with false claims. While Mark Zuckerberg himself was public about our interest in offering our services in China and details were widely reported beginning over a decade ago, the fact is this: we do not operate our services in China today.”

The hearing comes just days before Meta’s massive antitrust trial is scheduled to begin. The Federal Trade Commission’s case against the tech giant could force the company to divest Instagram and WhatsApp.