Former President Biden aide Anthony Bernal was subpoenaed on Thursday by House Committee on Oversight and Government Reform Chairman James Comer, R-Ky., in an investigation into the former president's mental acuity.

Comer issued the subpoena after Bernal, who was also former first lady Jill Biden's senior adviser, decided not to appear for a closed-door interview after the White House waived executive privilege for former Biden officials, Fox News reported. The subpoena is for a July 16 deposition.