Former Donald Trump attorney Rudy Giuliani has been interviewed by federal investigators as part of the special counsel’s investigation into efforts to overturn the 2020 election results, multiple sources familiar with the meeting told CNN.

The meeting between Giuliani, his attorney Robert Costello, and investigators took place in recent weeks. The sources declined to say what investigators’ questions focused on during the meeting, which has not been previously reported.

CNN Exclusive: Rudy Guiliani interviewed in special counsel’s 2020 election interference probe