Attorney General Bill Schuette's office says an investigation of the "Courser-Gamrat matter" is already open.
Spokesman John Sellek says the office is working with Michigan State Police on a "complete and thorough" investigation "without fear or favor, but declined to offer any details Friday.
The House Business Office says it found dishonesty, misconduct and misuse of public resources by Reps. Todd Courser and Cindy Gamrat, allegations that led to his resignation and her removal from office.