Government prosecutors may be investigating 21st Century Fox for quietly settling sexual harassment claims against former Fox News chief Roger Ailes without reporting it to the media giant’s shareholders.

On Wednesday, during a hearing before New York Supreme Court Judge David Benjamin Cohen, an attorney for former Fox News host Andrea Tantaros said he’s been served with a subpoena by federal prosecutors investigating sexual harassment allegations directed at Ailes. Tantaors, who once served as a co-host of the afternoon show The Five, alleges in her lawsuit that Fox News “operated like a sex-fueled, Playboy Mansion-like cult.”

In the midst of the hearing over Tantaros’ lawsuit against Fox News executives, her attorney Judd Burstein said he received subpoenas from federal investigators at the Department of Justice’s New York Southern District. “Once I saw it, I knew what was happening,” Burstein said. “They were investigating whether Fox News violated securities laws by not reporting settlements to the Securities and Exchange Commission.”