Illinois House Speaker Michael Madigan says Auditor General Frank Mautino will be “vindicated.”
Mautino has been auditor general since January.
He's under scrutiny for campaign expenses from his time as a state representative.
He has acknowledged there's a federal investigation, and the state board of elections is holding hearings.
Madigan says Mautino will come out on top when they're finished.
"I think it's appropriate that there would be an inquiry, which is happening. Certain issues have been raised. Frank Mautino has been responding to those issues. He will continue to respond to those issues,” Madigan said.
Questions into checks Mautino's campaign wrote to a service station and a local bank have led some Republican legislators to call for him to resign as the state's auditor.
But the Republican governor -- Bruce Rauner -- has indicated calls for resignation are premature, and the investigations should first play out.
Mautino's spokesman had no comment.