Who should be notified if you find that your employer is aiding child support fraud?

I work for a company that helps employees avoid child support by paying part of their wages to their spouse who does not work for the company. I sent an email to child support enforcement but haven't heard anything. Sitting on hold while trying to call their office isn't the most pleasurable experience in the world either. What agency can I notify who will actually follow up on this? I think this is a terrible way to be a deadbeat and I still can't believe the employer does this.