The US Federal Trade Commission (FTC) interviewed Facebook CEO Mark Zuckerberg this week as part of its anti-competition probe into the company, news website Politico reported.
The testimony was conducted under oath over the course of two days this week, said the report on Thursday, citing unnamed people familiar with the matter.
While investigations by the FTC do not always lead to the filing of lawsuits, this testimony could help the agency to build a case against the social networking giant.
The FTC, which has been conducting the antitrust probe into Facebook for over a year now, did not comment on the report.
“We are committed to cooperating with the US Federal Trade Commission’s inquiry and answering the questions the Agency may have,” a Facebook spokesperson told The Verge.
Zuckerberg last month also testified before a US Congress panel in relation to the House Judiciary Committee’s antitrust investigation into four big tech companies including Facebook.
The Facebook CEO faced tough questions from the panel on acquisitions of Instagram and WhatsApp.
The FTC last year imposed a record $5 billion fine on Facebook over its ties with the now defunct political analytics firm Cambridge Analytica and other privacy violations.