The US Federal Trade Commission is reportedly considering taking sworn legal testimony from Facebook CEO Mark Zuckerberg and COO Sheryl Sandberg.

Facebook CEO Mark Zuckerberg and COO Sheryl Sandberg could be asked by the Federal Trade Commission to provide sworn legal testimony as part of a yearlong antitrust probe conducted by the agency, The Wall Street Journal reported on Friday. 

Last year, Facebook revealed that the FTC had launched an antitrust investigation into the company. The agency is reportedly focusing on whether Facebook’s purchases of companies such as photo service Instagram and messaging app WhatsApp were part of the social media giant’s strategy to stifle competition.

The FTC is considering deposing Zuckerberg and Sandberg, and Facebook is preparing for the possibility, the Journal reported. During a sworn legal testimony, the participants commit to telling the truth and they could face perjury charges if there’s evidence they lied. Facebook officials are reportedly worried about the potential deposition of the company’s executives, according to the Journal.

The FTC declined to comment. Facebook didn’t immediately respond to a request for comment.

Zuckerberg is one of the tech executives scheduled to appear before the House Judiciary Antitrust Subcommittee in an antitrust hearing on July 27. Apple CEO Tim Cook, Amazon CEO Jeff Bezos and Alphabet and Google CEO Sundar Pichai are also expected to participate. 

This isn’t the first time Facebook has faced an inquiry by the FTC. Last year, the agency fined Facebook a record-setting $5 billion for alleged privacy missteps in the wake of the 2018 Cambridge Analytica scandal. Cambridge Analytica is a UK political consulting firm that harvested the data of up to 87 million Facebook users without their permission.